Blu Ray Media Stores: Buy.com Review

Blu Ray blank media guide : Best Blu Ray media stores
Best Blu Ray Media Online Stores Part 6: Buy.com Review

Buy.com often shows up in shopping engines as a good place to find well priced, difficult to find items, yet appears, at first site to have a ridiculously small inventory. When we dug a little deeper we actually found out that there is a larger mother lode of Blu Ray media to be found in a secret stash, some of it with excellent prices...

Site and usability
Blu Ray media can be found on the Buy.com site under Optical Media -> Blu Ray Media, but for some reason the category so identified does not display more than a very small number of choices. To get to the "real" inventory of Blu Ray media, one has to go to Computers -> Supplies & Media -> Media & Cleaning Cartridges -> Optical CD/DVD/Magneto Media, then refine results using the keyword "Blu Ray."  Site speed is dismal, with 7.0 seconds per page average to display a right-clicked SKU, although, probably due to caching, a regular left-click will display the same page in 3.5 seconds. Of our wish list of 13 types of sorting and binning, Buy.com provides a lowly 4: you do not have a Blu Ray category, cannot select speed, type, single/ dual layer, printability,  or quantity, cannot sort by best rating or most reviews, and need to calculate price per disk yourself. On the other hand, you can select the manufacturer, sort by best selling price, or manufacturer, and view user ratings on the listing pages.

Inventory and price
Buy.com shows off a total inventory of 117 Blue Ray media, and stocks a solid 31% of our 89 Blu Ray test media. - ranking 4th of all stores surveyed, after MediaMegaMall, Amazon and RunTechMedia. Buy.com prices are on average 25.4% higher than the best price across our surveyed stores, fourth highest after Provantage, SuperMediaStore, and B&H.  Interestingly, Buy.com has the best price for 5 SKUs, for media stocked by more than one store, rating 4th after MediaMegaMall, NewEgg and Amazon - much better under this criterion that when looking at the average overprice. This tells us that Buy.com has a fairly wide range of prices, with some excellent prices and some very bad ones...Some of the best prices are met when Buy.com is the actual distributor as opposed to marketplace merchants. Buy.com stocks 3 of the 6 media we selected for best Blu Ray archival grade media, for a low overprice of 12% over best price across the category.

User reviews
Buy.com gives its users the ability to write user reviews, which are common in some parts of the site. In the Blu Ray media area, however, user reviews are practically nonexistent, totaling 17 across all Blu SKUs.

Customer Service
Like Amazon, Buy.com has a very significant marketplace component, with various merchants selling directly to consumers in the Buy.com space - it probably pays a heavy price for it in its CS ratings. It gathers more than 4,000 reviews on ResellerRatings with a lowly 81% rating. It gathers an astounding 255,000 reviews on Google Shopping with a slightly higher 86% rating, and receives a low 81% ConsumerPla.net predictive CS rating.

Table: Buy.com Blu Ray media review (see legend below)

Conclusion
Buy.com is a general purpose shopping site with a large marketplace component, with poor site speed and sorting, an uncomfortable browsing experience, average inventory, some of the best and worst prices at the same time, and mediocre customer service. While it should not be relied on as the primary shopping site for Blu Ray media, with some excellent prices it is probably a site to check out when looking for good pricing opportunities, as long as service (such as delivery time) is not a critical part of the purchase.

Next we review MediaMegaMall for blank Blu Ray media... So come back soon!

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Table Legend:
Total inventory: total number of Blu ray media SKUs on the site
Inventory %: percentage of ConsumerPla.net list of 89 Blu Ray media that can be found at the store
Inventory % for selected archival media: % of SKUs that we selected in our Blu Ray Media review for archival grade
Site sorting: how many types of sorts and bins are possible on the site (out of the 13 we listed in our wish list)
Average query speed: the average speed to display a right-clicked SKU  - measures browsing speed
Average overprice: How much % over best price, for all media present in more than one store
Average overprice for selected archival media: specifically how much % over best price for the media we selected for archival grade
# lowest priced SKUs: how many SKUs in the store equal best price (if more than one store carries them)
# user reviews: how many user reviews we found on the site for Blu Ray media
Predictive CS rating: our worst case analysis of the likely Customer Support rating for this store, explained here

UPDATED: No Keyloggers on Samsung Laptops

UPDATED: GFI Labs, manufacturer of the anti-malware scanner VIPRE used by Mohamed Hassan, confirms that there is no keylogger on Samsung laptops, and that detection was a false positive. Our headline was changed to reflect the news.

Computer security: we generally expect to get spyware from infected mails or sites. It is unusual to get some directly from a computer manufacturer, and even more unusual for spyware in a brand new computer to have been put there voluntarily by the manufacturer. Yet a professor of Information Systems at the University of Phoenix has discovered keyloggers on two brand new models of Samsung laptops (R525 and R540), apparently installed by Samsung itself.

Mohamed Hassan, an adjunct professor of Information Systems in the School of Business at the University of Phoenix, and the founder of the security firm NetSec Consulting Corp, found a copy of the commercial keylogger StarLogger in a Samsung R525 laptop that he had purchased for his personal use. After returning it and buying a Samsung R540 model instead, he found the same keylogger in the same directory of his new laptop. He contacted several Samsung staff. A support supervisor confirmed that the keylogger had been installed by Samsung "to monitor the performance of the machine and to find out how it is being used." Samsung PR did not respond to requests by Dr. Hassan for a week, after which Dr. Hassan went public.

A keylogger is able to capture any keystroke you type on your computer, including passwords, and send them to an outside party. Softpedia describes StarLogger's capabilities as follows:

"Do you want to know what your buddy, colleague or employee is typing? What are they doing on the computer? StarLogger records every keystroke made on your computer on every window, even on password protected boxes.

This key logger is completely undetectable and starts up whenever your computer starts up. See everything being typed: emails, messages, documents, web pages, usernames, passwords, and more. StarLogger can email its results at specified intervals to any email address undetected so you don't even have to be at the computer your are monitoring to get the information. The screen capture images can also be attached automatically to the emails as well as automatically deleted."

If you have a Samsung laptop, find out if it has a special guest: CNET already published instructions to find out if StarLogger is present on your laptop, and to remove it if you find it there. If you are shopping for a laptop - do try to avoid buying one that comes with a keylogger.

It is hard to believe that a company of Samsung's size and reputation would do take such an idiotic - and probably illegal- step. If they truly did it - what were they thinking? Who had the bright idea - and - who authorized it? This would be a hard story to pass on your resume.

Update 3/31/2011, 10:55AM PST: as indicated in our earlier twitter post 6 hours ago (:-),  the keylogger detection was a false positive by scanning software VIPRE. Early on, ZDNet figured out how to duplicate the false positive by creating an empty directory with the right (or wrong...) name. Security company F-Secure, shortly afterwards, posted that they could not find keyloggers on Samsung laptops. Samsung came out denying the allegations, and pointing at malware scanner VIPRE as the culprit for a false positive detection. Later this morning, GFI Labs, maker of VIPRE, confirmed that the keylogger detection was a false positive:

"A Network World article has alleged Samsung laptops of having a keylogger.  Unfortunately (and to our dismay), the evidence was based off of a false positive by VIPRE for the StarLogger keylogger. 

The detection was based off of a rarely-used and aggressive VIPRE detection method, using folder paths as a heuristic.  I want to emphasize “rarely”, as these types of detections are seldom used, and when they are, they are subject to an extensive peer review and QA process.  (It’s not common knowledge, but folder path detections are actually used by a good number of antimalware products, but are generally frowned upon as a folder that looks clearly like one for malware has the potential of generating just this kind of result — a false positive.)

The directory in question was C:\WINDOWS\SL, and is the Slovenian language directory for Windows Live.  This same directory path is used by the StarLogger keylogger."

So all's well that ends well. The hubbub about this story, however, points out a few issues of interest:

• How did Network World, who broke the story, check it prior to publishing? It would not have been difficult to line up a couple of *real* security experts to look over the event and confirm the finding. In fact, it appears, post facto, that a simple inspection of the suspicious directory would have been enough to find out that there was no keylogger.

• Why did it take a week for Samsung to respond (or not respond) to such an allegation? This was a very serious issue, yet nobody seems to have minded the store. 

• False detections are a very common occurrence in virus/spyware scanning software. We do not feel that GFI Labs really needed to apologize for it., On the other hand, the original security "expert" would have been well inspired to have double or triple checked its keylogger detection by the use of additional tools, along with visual inspection, prior to leveling a major accusation, which now turns out to be unfounded.

• If you run into a suspicious malware issue, you can upload the file in question to virustotal, a web-based malware analyzer which runs multiple malware detection engines to validate detection.

Our apologies to Samsung for reporting suspicions which were untrue.

Want to read more about it? Try Network World #1 and Network World #2 (they broke the story),  CNET, Washington Post, ZDNet, PC World, Financial Times,  TIME, msnbc,  eWeek, Computerworld, PCWorld, CrunchGear #1, CrunchGear #2,  Forbes, Naked Security or Lifehacker Australia.

Blu Ray Media Stores: Beach Audio Review

Blu Ray blank media guide : Best Blu Ray media stores  
Best Blu Ray Media Online Stores Part 5: Beach Audio Review

Beach Audio often shows up on shopping engines with decent prices. We researched it in depth, expecting to see it appear among the best. After a thorough investigation, we were disappointed by some of its marketing and customer service practices.

Site and usability
Blu Ray media can be found on Beach Audio under Blank Media -> Storage Media -> CD/DVD Media. They share the category with CDs and DVDs, but can be isolated under the selections Blu Ray Recordable Media (BD-R) and Blu Ray Rewritable Media (BD-RE). By checking both categories you effectively select all Blu Ray media, which is the equivalent of having a Blu Ray category.  Site pages load comparatively slowly, with an average 4.5 seconds to display a right-clicked SKU. Of our wish list of 13 types of sorting and binning, Beach Audio provides 9: you cannot sort by best rating, most reviews or best selling, and you have to calculate unit price yourself. On the other hand, you have the equivalent of a Blu Ray media category,  you can select type (BD-R/ BD-RE), by single/ dual layer, printability, speed, quantity and manufacturer, you can view user ratings in the listing pages, and you can sort by price and manufacturer.

Inventory and price
Beach Audio's inventory totals 77 different Blu Ray media, an average inventory for the category. It stocks a low 18% of our 89 test Blu Ray media - 4th lowest before Provantage, TapeOnline and B&J Photo Video. Beach Audio's average overprice over best price across the stores we surveyed was 14.2%, which is low for the industry, and puts Beach Audio 4th in the category, after MediaMegaMall, TapeOnline and NewEgg. On the other hand, Beach Audio only has 2 SKUs match the best price across all stores surveyed, ranking 3rd last, even with SuperMediaStore, and before Rima and BHP Photo Video. Beach Audio stocks 3 of the 6 Blu Bary media that we selected as best archival grade media, with a low average overprice of 11.5% over the best price in the category for the basket of them.

User reviews
Beach Audio lets the user write user reviews, but so far very few have been written. We could only find 10 reviews across the whole site.

Customer Service
Beach Audio only gathers a bit over 300 reviews with ResellerRartings, with a very low rating of 78%. It does better on Google Shopping, raking up more than 4,000 reviews with a good rating of 94%. In our overall predictive CS rating, it scores a low 83%, even with Buy.com and only ahead of MediaMegaMall. Most common issues had to do with advertised prices and canceled orders.

Table: Beach Audio Blu Ray media review (see legend below)

Conclusion
Beach Audio carries a average inventory of Blu Ray media, with overall good but not record prices, decent site capabilities, practically no user reviews, and a rather poor CS record. Its pricing is good for our basket of selected archival grade Blu Ray media. While do not see many reasons to shop there for Blu Ray media unless you already have a cart going for other purposes, Beach Audio is worth visiting for a price check unless service (delivery time, for instance) is an important aspect of the purchase.

Next we review Buy.com for Blu Ray media... So come back soon!

<<Previous                                                                                                                     Next>>

Table Legend:
Total inventory: total number of Blu ray media SKUs on the site
Inventory %: percentage of ConsumerPla.net list of 89 Blu Ray media that can be found at the store
Inventory % for selected archival media: % of SKUs that we selected in our Blu Ray Media review for archival grade
Site sorting: how many types of sorts and bins are possible on the site (out of the 13 we listed in our wish list)
Average query speed: the average speed to display a right-clicked SKU  - measures browsing speed
Average overprice: How much % over best price, for all media present in more than one store
Average overprice for selected archival media: specifically how much % over best price for the media we selected for archival grade
# lowest priced SKUs: how many SKUs in the store equal best price (if more than one store carries them)
# user reviews: how many user reviews we found on the site for Blu Ray media
Predictive CS rating: our worst case analysis of the likely Customer Support rating for this store, explained here

550 Paracord, Universal Utility Line: Cool Gear

Mil-C-5040H Type III 550 paracord, or Mil-C-5040H Type III parachute cord, is an amazingly universal tool that can be used in many different circumstances to improvise repairs, like duct tape, as dictated by your environment. Originally produced for parachutes in the second World War, its lightness and compactness combined with its versatility quickly turned it into a must-have piece of equipment across army units of all kinds. Ex-servicemen quickly spread its popularity to the general population.

What do its users think of it? This is what we collected from numerous forums and reviews: "It is the handiest stuff that I have ever seen... strong, light and durable... There are 1000 uses for it... I highly recommend it to everyone... You can never have enough paracord around... Many uses for this product... Small, lightweight, and strong... Everyone should have great quality [para]cord... So many uses....  Uses are endless and worth having around for almost everything...  This cord is the perfect all-purpose camping cord.... You might be able to break it with a large truck but I wouldn't bet on it... Toss a ream of it in your vehicle and leave some at home too... If you are an outdoorsman or outdoorswoman and you don't have a 1000' roll of this in you gear then you just aren't really serious about it... I didn't know I needed it until I got it... This stuff is amazing! It is very tough and cut-resistant.... A must have for any hunter and outdoor person and survival kit... An absolute necessity in a survival kit... As important as a knife... I have [boy scouts] wrap cord around their hiking sticks as a hand grip material; then there's always some on hand in an emergency.. There isn't a weekend that goes by that we don't use it and my boys are always finding new uses..." 

The one we like best is: "with a 1000' roll of this and two rolls of duct tape I think someone could take over the world!!"  


Why is it so popular?

• It is very light for its strength. As its name indicates, its breaking strength is rated at 550 lbs, yet 10 feet of length can be carried on your wrist in the form of a woven bracelet. A pound of 550 paracord will produce at least 225 feet of line.

• It is impervious to water, being made of nylon. 

• It does not fray easily, as it can be terminated cleanly by burning the end with a lighter or a match.

• It has strong resistance to light exposure per its original specification, and, as a result, ages well in outdoor use.

• Each length of 550 paracord can produce 7 to 9 times its length in much thinner line, since it is possible to extract the guts for other purposes, such as fishing line, sutures, etc. In turn, each gut can be unstranded into 3 smaller yarns, although these can be somewhat twisty. While there is no performance difference between 7x, 8x and 9x cores, we have a slight preference for 8x or 9x cores because we can get more gut length out of the same length of 550 paracord, since we have more core yarns.

• The sheath and its yarns can also be used independently. The sheath is woven of 32 or 36 yarns, which can also be reused to weave material.

• The versatility of 550 paracord makes it ideal as a light universal rope in outdoor activities. It is highly prized by survivalists. Many users carry a woven bracelet, neck lanyard, or belt of paracord for possible reuse. Others wrap flashlight or knife handles with it for the same purpose.

Mil-C-5040H Type III 550 paracord drawbacks

• Abrasion is a risk, as it is not resin-impregnated, although the sheath/ core construction provides some protection. 

• The great elasticity of the cord, which gives it its high breaking strength, is also a weakness for some uses as it can lengthen under strain 30% or more. This will rule out some potential uses where constant length is important. For instance, it would not be wise to use 550 paracord to make a metal canoe fast on the top of a car, as the cord would easily stretch and let the canoe fall in a big gust... 

What it is being used for

We collected some of the uses that people have put it to. One user describes emergency surgery: "I didn't see ... barbed wire... and I ended up with two deep gouges... I cut some 550 cord, pulled out the seven interior strands, and divided the 2-ply strands again. Those were my sutures. A # 8 snelled hook served as the needle, and I used a Leatherman tool to pull the hook through. I gave it 6 stitches... A week later, I removed the stitches, and although they held the wound tightly together, the skin did not adhere to the nylon threads." The variety of uses is quite remarkable: "wall tent, clothes lines... In a group camp usually someone want a piece of cord for something and bingo, here it is... Hang a hammock... Fishing line, net weaving, stitching, and netted containers... I once used the exterior sheath of 550 to weave a small hammock... My primary shelter-lashing material when making lean-tos, wickups, and tarp-shelters...Perfect for hauling up your gun or bow up to the tree stand, the BEST boot laces ever, I've used it to help stake out my tent... This is one of the first thing I add when making a emergency survival kit for someone. Not only is it strong and lightweight, you can separate the strands for even more length. (Each separate cord, and there are 7, is good for about 50 lbs.)... Bought 2 x 100ft rolls and renewed cords on 50 two man tents. Has worked a treat. Good and strong to handle the New Zealand's southern weather conditions... Inner cords can be used for fishing line, sewing repairs, lashing, snares...  Hang antennas from trees... or to tease the cats with... I had to set up a tarp canopy between some oddly placed trees because we were expecting rain in the morning... Everything from making your own parachutes to tying your tent down... I used the cord to set a Z-Drag lift system, using carabiners, in my basement to lift an approximate 400 lb band saw so I could put it in a movable base... I used this rope wile working in Haiti, It really held up to the heat, moisture, and dusty terrain. It held up great, very good product for multiple purposes...  Rope ladder... Survival bracelets - one bracelet up to 30 ft cord... Key rope around the neck 3 ft or so... Braided key rope around the neck 25 ft... Gun straps 100 ft... Boot laces 8 ft... Backpack straps braided triple solomon 20 ft... Knife lanyards... Multi tool lanyards... Small loops to hang off your belt... Made rope swing at the river with it 70 ft french braided wood handle... Lashed together a few make shift beds lean tos... Pulled a car outa the snow with it once triple lapped cord 30 ft then tied off to Jeep pulls minivan slowly carefully out lol... Sleeved a few computer wires with it... Used as a fish stringer few times... Used it for hauling a few couches few times...  Took 20 foot in 6 in sections removed all the inner cords filled it with lead for fishing weights, no more snags... I bought this for a knife handle wrap and it worked perfectly... Ridge lines for tarps... Shoelaces... Hanging food from bears... Vehicle Tie Downs... Sewing fabric... Making a fire bow... Fishing line... String for a bow... Making a shelter...  Fish gill nets...  Animal snares... Anchor line... Binding... Twine... Animal restraints... Dental floss... Splints... Tourniquet."

The use description we like best, though, is this one (we are not sure about its truthfulness though): "tying up burglars (or your wife), securing split trees, rappelling down buildings during the apocalypse, restraining zombies, or zombie dogs, and/or camping. You simply cannot beat the versatility of this product.
Side-note: Given how well it works on zombies, I feel it would work equally well on were-wolves and vampires."


The trap of commercial paracord

True mil-spec paracord is specifically referenced as Mil-C-5040H TYPE III parachute cord or Mil-C-5040H TYPE III 550 paracord ("Mil-C-5040 TYPE III" without the H is also good), and  the cord batch carries a testing certificate guaranteeing its performance. Commercial paracord, however, is not tested, and often carries significantly lower performance. Some samples of commercial paracord use different, cheaper, materials, for the core yarns or  for the sheath, or a lesser number of core yarns. Some of them have very low breaking strength, or use material that degrades quickly. So, when you buy commercial paracord, as opposed to Mil-C-5040H Type III 550 paracord, you do not have any guarantee of performance.

A common way to advertise commercial (i.e. with no guaranteed performance) paracord is by calling it  "mil-spec 550 paracord." This is NOT for Mil-C-5040H TYPE III 550 paracord - it could be for any quality of commercial paracord, with no way to know what the breaking strength of the paracord will be. Trustworthy vendors who sell commercial paracord will specify that it is not made for parachuting applications.


The trap of Type II or Type IIA paracord

The Mil-C-5040H military specification defines 6 types of paracord: type I with braking strength of 95 lbs, type IA, with breaking strength of 100 lbs, type II with breaking strength of 400 lbs, type IIA with breaking strength of 225 lbs, type III with breaking strength of 550 lbs, and type IV with breaking strength of 750 lbs, which is difficult to find. Many items labeled "paracord" or "mil-spec paracord" without a mention of 550 lb breaking strength with be type II or type IIA paracord, with a minimal breaking strength which is significantly lower than 550 paracord. This is even worse than the manifestly falsely advertised "mil-spec 550 paracord" items. In particular, most bracelets or lanyards made of "paracord" are typically made of type II or type IIA commercial paracord.


Colors

True Mil-C-5040H TYPE III 550 paracord only comes in white, black, camouflage colors, or international orange, due to the original military specifications. Cool colors are available in commercial versions (including interesting reflective colors). We recommend using two colors, one earth or green color for camouflage uses such as hanging food outside the reach of bears, and international orange for other uses.  


Buying Mil-C-5040H TYPE III 550 paracord

In order to buy Mil-C-5040H TYPE III 550 paracord, with guaranteed breaking strength, you need to buy paracord that is advertised exactly as "Mil-C-5040H TYPE III parachute cord," "Mil-C-5040H TYPE III paracord," or "Mil-C-5040H TYPE III 550 paracord." The better sites will also publish the official certificate of compliance (i.e. test verification) from their paracord tests. True Mil-C-5040H TYPE III 550 paracord is 30-70% more expensive than cheap commercial 550 paracord, but only slightly more expensive than good quality paracord.


Where to buy Mil-C-5040H Type III 550 paracord

We recommend buying paracord from vendors who focus on sky jumpers, parachutists or emergency workers, because their paracord is much more likely to buy the true Mil-C-5040H Type III 550 paracord. For the same reason, we recommend buying a USA-made product.There are very few sites where you can find the true blue item. Best Glide is a provider of aviation survival equipment, and provides a certificate of compliance. Best Glide carries all regular military colors. Adventure Survival Equipment, a division of Best Glide, is also a good online choice. ParaGear is a paruchuting store.   LifeView Outdoors is a  retailer of recreational outdoor gear.

If you are willing to compromise down to high quality commercial 550 paracord,where you will find a better set of colors, but non-guaranteed performance, you might want to check out Cabela's, TakKnife, CheaperThanDirt , CountyComm or  CampingSurvival. 


Statistical user ratings

We could not find a statistically significant set of user reviews for true Mil-C-5040H Type III 550 paracord, so we looked for user reviews of decent quality commercial grade 550 paracord. We found 211 reviews, of which 195 were positive, for a 92% approval rating, with a 3.6% margin of error at 95% certainty. This represents an excellent rating, which could only increase if applied to true Mil-C-5040H. A presentation of our rating methodology can be found on ConsumerPla.net Statistical Ratings Explained.


Conclusions

• Mil-C-5040H Type III 550 paracord is an extraordinarily versatile general purpose utility line, as useful as duct tape.

• It is light and compact, with high tensile strength, and can fit into any survival or mini-tool kit. It is almost a required part of any such kit, and is highly appreciated by its enthusiastic users.

• True MIL-C-5040H Type III 550 paracord is superior to commonly found commercial "mil-spec" paracord, and can be found in a few sites, such as Best Glide, a provider of aviation survival equipment.

Want to read more about it? Try Cool Tools, Outside Magazine, Survival Topics. or this excellent Wikipedia article. The Survival Forum, which is not a survivalist forum, but an emergency gear forum, is an interesting place to discuss paracord use. There are many sites with tutorials on specific paracord braiding projects, along with YouTube tutorials - Stormdrane's Blog has many projects illustrated over the past few years. General purpose braiding sites, such as Boondoggle Man, also provide excellent references. The actual MIL-C-5040H specs can be found with the DoD, or on EverySpec. Essex Mills published, in 1954, a Test Report on MIL-C-5040.

Blu Ray Media Stores: B&H Photo Review

Blu Ray blank media guide : Best Blu Ray media stores
Best Blu Ray Media Online Stores Part 4: B&H Photo Video Review

B&H Photo Video is well known to photo enthusiasts as a high quality, well priced online store with excellent customer support.  Its traditional rival is Adorama, which, however, is not really present in the Blu Ray media market a this time (we screened Adorama here).

Site and usability
Blu Ray media can be found on the B&H site under the Film, Tape, Media Tab: Film, Tape, Media -> CDs, DVDs and Other Blank Media. While they are under the same category as other optical media, it is not hard to isolate them, as there are specific selection bins for BD-R and BD-RE, which you can both select to get the equivalent of a Blu Ray category. With an average 2.0 seconds to display a right-clicked SKU, the site speed is decent, although not blinding fast. Of our wish list of 13 types of sorting and binning, B&H provides 9: you cannot select speed, cannot sort by best selling, or most reviews, and need to calculate price per disk by hand. On the other hand, you can access the equivalent of a Blu Ray category, select type (BD-R/ BD-RE), single/ dual layer, printability, quantity and manufacturer, sort by search relevance, price, manufacturer and best rating, and view user ratings on the listing pages.

Inventory and price
B&H Audio Video totals right now 63 SKUs for Blu Ray media, a relatively narrow inventory. It stocks a low 13% of our 89 test Blu Ray media - lowest of all of the reviewed stores, even with TapeOnline. B&H Video prices are on average 29.4% higher than the best price across our surveyed stores, third highest after Provantage and SuperMediaStore, and slightly ahead of Buy.com and RunTechMedia. While, clearly, any store is, on average, higher than the best price (no store can have, on average, the best price for all media), 29.4% is high. B&H Audio Video matches best price for one SKU, for media stocked by more than one store. This is the lowest number across stores surveyed, even with Rima. Of the 6 best Blu Ray media we selected for archival grade storage, B&H stocks 2, with a 43.4% overprice over best price in the category.

User reviews
B&H Photo Video has a limited number of user reviews, for which the average ratings can be seen on the category listing pages. It totals 86 reviews across all Blu Ray media SKUs, which, given the total inventory, is not enough critical mass to reliably gauge the quality of specific Blu Ray media when shopping on the site.

Customer Service
Where B&H Audio Video truly stars is in customer service and support (CS). It has very large numbers of reviews both with ResellerRatings and Google Shopping, and gets outstanding 98% ratings from both, as well as a category-high 98% in our predictive CS rating, even with Rima and TapeOnline. Given its astonishingly high numbers of reviews as well as ratings, we can be sure of a very high quality of service.

Table: B&H Photo Video Blu Ray media review (see legend below)

Conclusion
B&H Audio Video is a general purpose shopping site, with decent site speed and sorting, narrow inventory, rather high prices on average, and outstanding customer service. While we cannot place it among the top online media stores, it is a good place to buy media if you are already shopping on the site for other items, as long as price is not an essential criterion.

Next we review Beach Audio for blank Blu Ray media... So come back soon!

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Table Legend:
Total inventory: total number of Blu ray media SKUs on the site
Inventory %: percentage of ConsumerPla.net list of 89 Blu Ray media that can be found at the store
Inventory % for selected archival media: % of SKUs that we selected in our Blu Ray Media review for archival grade
Site sorting: how many types of sorts and bins are possible on the site (out of the 13 we listed in our wish list)
Average query speed: the average speed to display a right-clicked SKU  - measures browsing speed
Average overprice: How much % over best price, for all media present in more than one store
Average overprice for selected archival media: specifically how much % over best price for the media we selected for archival grade
# lowest priced SKUs: how many SKUs in the store equal best price (if more than one store carries them)
# user reviews: how many user reviews we found on the site for Blu Ray media
Predictive CS rating: our worst case analysis of the likely Customer Support rating for this store, explained here

Air Filters: Does Air Flow Impact Mileage?

Best Air Filters Review: Air Filter Facts
Air Filter Facts Part 5: Air flow and mileage

Can air flow improve your vehicle's fuel economy? Many users report improved mileage upon the adoption of an air filter with measurably increased airflow, such as when you change from a stock OEM filter to a K&N filter. They are (mostly) wrong.

We already proved that different air filters can increase (or worsen) air flow (+/- 0.5kPa), and that clogged air filters  significantly impact air flow (up to +6.25 kPa, much higher impact than air filter swap). How does air flow impact mileage?

Fueleconomy.gov  is a federal government site focused on - guess what - fuel economy.  Under their aegis, the famed Oak Ridge National Laboratory published, in February 2009, a investigating the effect of air filter condition (i.e. air flow restriction) on fuel economy. They were able to show, once again, that aftermarket (high flow) filters were able to provide more air flow than OEM filters, measuring a lower pressure loss across aftermarket filters than OEM filters:

The February 2009 Oak Ridge National Laboratory research report on fuel economy measured the difference in mileage between a clean, new air filter, and the severely clogged air filters we showed in our last post. The researchers experimented with both modern fuel-injected engines, and with older carbureted engines. Despite the difficulty at getting very low airflow, the difference in fuel efficiency for all newer vehicles was statistically nonexistent, as shown below for one of the experiments (for this illustrative graph, we picked the Dodge Charger, which showed, in our previous test, the worst clogging):

Oak Ridge National Laboratory's conclusion: "Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR [air fuel ratio] regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10–15%) decrease in fuel economy [...] was so severe that the vehicle was almost undrivable."

If clogging the air filter - which increases restriction to air flow by 6.25 kPa -  does not have an effect on mileage,  then clearly, swapping air filters - which varies air flow restriction by +/- 0.5kPa -  certainly does not impact mileage either.

There is an important note to add to the Oak Ridge's results: the vehicles tested were all gasoline engines. Normal diesel engines are unthrottled in normal use after warm-up, which means that, even under light loads, they operate at high air flow, and throttle cannot be used to adjust fuel fix. It is possible that air filters could impact fuel consumption for modern diesel engines.  

We found multiple confirmations for the conclusions of the Oakridge National Laboratory's tests. For example, Consumer Reports, in 2011, published a post on fuel economy, and listed dirty air filters under myth busters (...): "Our tests show that driving with a dirty air filter no longer has any impact on fuel economy, as it did with older engines. That's because modern engines use computers to precisely control the air/fuel ratio, depending on the amount of air coming in through the filter. Reducing airflow causes the engine to automatically reduce the amount of fuel being used. Fuel economy didn't change [...]." Offroad Adventures tested a high flow drop-in filter replacement and found no impact to mileage: "Flow capacity is 15-20 percent higher than stock, so it gives you a little over-capacity for mods. We ran the panel in the stock housing for several months and noted no change in fuel economy."

All the scientific evidence clearly points at the same conclusion: air flow in modern vehicles does not impact mileage. Everything else being equal, high flow filters with higher air flow do not improve a vehicle's flow efficiency. In fact, several studies (e.g. Fodor & Ling, "Friction reduction in an I.C. engine through improved filtration and a new lubricant additive", Lubrication engineering, 1985, vol. 41, no10, pp. 614-618; Andrews, Li, Jones, Hall, Rahman & Saydali, "The Influence of an Oil Recycler on Lubricating Oil Quality with Oil Age for a Bus Using In-Service Testing,"SAE 2000 World Congress, Paper 2000-01-0234) have shown better mileage resulting from better oil filtration. As a result, is possible that filters with higher air flow but worse filtration (these two traits often go hand in hand), which contribute to more wear and more particles in the oil, may ultimately result in worse fuel economy.


Conclusion

• The choice of an air filter can materially impact air flow

• Air flow does not affect fuel economy in gasoline engines

• Drop-in high flow air filters have no effect on mileage in gasoline engines

But does air flow impact performance? Next we investigate the effect of clogged air filters on vehicle performance... So come back soon!

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Do Clogged Air Filters Restrict Air Flow?

Best Air Filters Review: Air Filter Facts
Air Filter Facts Part 4: Do clogged air filters restrict air flow?

In our previous post, we proved that different air filters can improve (or worsen) air flow when clean. But what is the impact, if any, of a clogged (or very dirty) air filter?

Our friends from Oak Ridge National Lab also investigated the impact of a clogged air filter. To simulate the appropriate level of reduced air flow, the researchers ended up stuffing shop towels (!!!) on the upstream side of the air filter's air box, or wrapping the filter itself in shop towels:

 

The shop towels had to be stuffed so hard to get to the right level of reduced airflow that the one of the air filters was quite damaged in the process:-) This is representative of the difficulty of getting severely restricted airflow... In the end, the study was able to restrict flow significantly:

 

It is worth noting that filters are typically considered clogged when pressure drop across the filter increases by 10" H2O, i.e. 2.5kPa. What this means is that the tests were run using significantly higher air flow restrictions. These are truly worst case tests.

Conclusion

• Clogged air filters significantly reduce air flow

Does this very significantly reduced air flow (to the degree that it sucked a shop towel into the intake) actually worsen fuel economy? Next we investigate how air flow impacts mileage... So come back soon!

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Blu Ray Media Stores: Amazon Review

Blu Ray blank media guide : Best Blu Ray media stores 
Best Blu Ray Media Stores Part 3: Amazon Review

One can find almost anything on Amazon, which is often the first resource that many online shoppers check when looking for unfamiliar items. And, sure enough, there are plenty of blank Blu Ray media on Amazon... In fact, thanks to Amazon's broad marketplace, where merchants other than Amazon itself can directly transact with consumers, we found Amazon to be an ideal place to locate unusual or rare Blu Ray media. Among other items, we were able to find numerous Japanese imports for Blu Ray media, a particularly interesting find as optical media distributed in Japan carries an excellent reputation around the world. In general, we found that, while Amazon did not always carry the best prics on the market, it had an amazingly deep inventory along with low prices for specific SKUs - but not for everything...

Site and usability
Blu Ray media can be found on the Amazon site under Computers -> Computer Accessories -> Computer Accessories (yes, twice) -> Blank Media, or under  Electronics -> Accessories & Supplies -> Blank Media, for the same result. Site speed is poor, with 3.5 seconds per page average to display a right-clicked SKU. Of our wish list of 13 types of sorting and binning, Amazon provides 7 of them: you do not have a Blu Ray category, cannot select speed, single/ dual layer, printability,  or quantity, cannot sort by most reviews, and need to calculate price per disk yourself. On the other hand, you can select the type (BD-R/ BD-RE), manufacturer, sort by best selling, price or manufacturer, and view user ratings on the listing pages.

Inventory and price
Amazon shows off a outstanding inventory of 292 Blue Ray media, and stocks a category record 44% of our 89 Blu Ray test media - ranking 1st of all stores surveyed, ex-aequo with MediaMegaMall. Amazon prices are on average 19.9% higher than the best price across our surveyed stores, ranking in the middle of the pack. Amazon SKU prices match the best price for 6 SKUs, for media stocked by more than one store, rating 3th after MediaMegaMall and NewEgg, much better under this criterion that for the average overprice. When we looked specifically at the 6 best media we selected for archival quality, we found that Amazon carries 3 of them, at an overprice of 18.5% over best price. We would have liked the percentage to be higher, and the prices a touch lower. Clearly, Amazon has a fairly wide range of prices, with some excellent prices and some rather poor ones. This broad set of prices (which we can also encounter at Buy.com) seems somewhat characteristic of sites with merchant marketplaces.

User reviews
Amazon is famous for its user reviews, and for their integration in the product pages. We often turn to Amazon first to check user reviews on a very wide variety of products. We were all the more disappointed to find only 392 reviews across all Blu Ray media SKUs on Amazon - a category-high number, yet somehow lower than our expectations...

Customer Service
Surprisingly for a site with the volume, loyalty and reputation of Amazon, it does not do very well in CS. Amazon gathers little more than 2,000 reviews on ResellerRatings with a low 83% rating, and a bit over 5,000 reviews on Google Shopping with a better 90% rating. It receives a mediocre 85% ConsumerPla.net predictive CS rating. This relatively poor performance is no doubt due to the presence of marketplace merchants.

Table: Amazon Blu Ray media review (see legend below)

Conclusion
Amazon is a general purpose shopping site with a large marketplace component, an amazingly broad inventory of Blu Ray media products, mediocre site speed and sorting, some of the best and worst prices at the same time, and mediocre customer service. It is definitely a good site to check for Blu Ray media, although not the most convenient or always the cheapest, and a great resource for unusual or rare media.

Next we review B&H Photo Video for Blu Ray media... So come back soon!

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Table Legend:
Total inventory: total number of Blu ray media SKUs on the site
Inventory %: percentage of ConsumerPla.net list of 89 Blu Ray media that can be found at the store
Inventory % for selected archival media: % of SKUs that we selected in our Blu Ray Media review for archival grade
Site sorting: how many types of sorts and bins are possible on the site (out of the 13 we listed in our wish list)
Average query speed: the average speed to display a right-clicked SKU  - measures browsing speed
Average overprice: How much % over best price, for all media present in more than one store
Average overprice for selected archival media: specifically how much % over best price for the media we selected for archival grade
# lowest priced SKUs: how many SKUs in the store equal best price (if more than one store carries them)
# user reviews: how many user reviews we found on the site for Blu Ray media
Predictive CS rating: our worst case analysis of the likely Customer Support rating for this store, explained here

Screening Blu Ray Media Stores

Blu Ray blank media guide : Best Blu Ray media stores
Best Blu Ray Media Stores Part 2: Screening Online Stores

The DVD reference site digitalFAQ.com has an excellent and well-maintained list of the best places to buy DVD blank media on line. When we reviewed the Blu Ray forums and the store offerings, we found out, however, that the best places to buy Blu Ray media on line were somewhat different from those from which to buy DVD media. In many cases, the Blu Ray blank media inventory of traditional CD/DVD media stores was poor, expensive, or sharply targeted at no-name or unreliable brands.We are listing below some stores that were referenced on line as being good sources, but failed our stringent requirements (:-), before listing our best picks.


These online stores did not make the cut

Adorama normally matches its excellent competitor B&H Photo move for move, and has excellent reputation among photo/ video amateurs. It practically does not have any Blu Ray media in stock. We are only mentioning it here because we researched B&H in depth.

Americal has limited inventory, a few SKUs with good to very good pricing, and a small set of rather poor store reviews. 

ANTOnline  has a very broad set of good store reviews, but a small Blu Ray media inventory, poor pricing, and no sorting to speak of.

CDRom2Go is often listed as a good CD or DVD media store, but its inventory of Blu Ray media is totally insufficient.

Colamco is a somewhat flawed storefront with early promise, but which disappointed us. We originally found it when searching for good pricing on some of our media selections: it showed up several times with great pricing. When exploring its inventory, however, we could never find the items we had looked up on a product search - they seem to be only reachable through Google price searches, as the categories do not reflect actual items in stock, even if they show on Google searches. The site seems heavily bugged. In addition, the ResellerRatings record is poor, and displays some worrisome CS stories.

J&R has a smallish, but not ridiculous inventory, mostly focused on lesser quality brands, poor site searching for Blu Ray media, decent sorting, and a small percentage of spindle packs. Its prices are on the high side.

Got Media's inventory of DVD media is broad and well priced. Its inventory of Blu Ray media, on the other hand, is largely limited to Verbatim, and its pricing is not exceptional in any way.

Overstock.com has a few interesting reviews, but very little Blu Ray media inventory, and pricing is poor.

PCRush is another site which we started researching with excitement, but which disappointed us. The site is popular and has good store reviews. The inventory breadth is decent, but much of it is junk media, and the quality brands rarely show in spindle packs (mostly jewel cases). Despite good pricing on a small number of SKUs, the site is expensive, and sorting is poor for Blu Ray media.

Staples has a great set of CD and DVD media reviews, although its brand selection is very narrow. It has practically no Blu Ray media inventory. 

TapeResources is an excellent resource of professional audio and video supplies. its customer service is excellent, and the ResellerRatings reviews are outstanding. The Blu Ray inventory, however, is limited, there are no user reviews, and prices are high.

Tapes.com has a mediocre inventory, unexceptional prices, no useful sorting, and some significant labeling issues (for instance, one of its popular BD-R DL products is called "rewritable," which wrongly indicates a BD-RE format).

TigerDirect is the most commonly mentioned rival for NewEgg in the market of computer parts and supplies. However, TigerDirect's inventory of Blu Ray media is mediocre, its pricing is all over the map - sometimes fair, sometimes gouging,-  it has very few user reviews, and its rating on ResellerRatings is poor.

Walmart has a very poor Blu Ray inventory, a few product reviews, and mediocre pricing.

Next we review Amazon for blank Blu Ray media... So come back soon!

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Best Blu Ray Media Stores Review

Blu Ray blank media guide : Best Blu Ray media stores
Best Blu Ray Media Stores Review Part 1: Best Online Stores Criteria

 The DVD reference site digitalFAQ.com has an excellent and well-maintained list of the best places to buy DVD blank media on line. When we reviewed the Blu Ray forums and the store offerings, we found out, however, that the best places to buy Blu Ray media on line were somewhat different from those from which to buy DVD media. In many cases, the Blu Ray blank media inventory was poor, expensive, or sharply targeted at no-name or unreliable brands. So, to investigate what the best online stores for Blu Ray media were, we went on Blu Ray fan forums, scouring references to the best stores, and we ran deep product searches on Google, going to the 25th page for most common Blu Ray media. This is what we found.


What Makes For a Good Blu Ray Media Store

Broad inventory
One the first attributes we looked at was the quality of the inventory. A good online store has to have a broad inventory of Blu Ray media, typically 50 to 100 different media, hopefully more. We need to be able to have a good choice of media, in each format (BD-R LTH, BD-R, BD-R DL, BD-RE, BD-RE DL). We prefer products with spindles, because the unit cost is typically much lower. In particular, we found some online retailers with a broad inventory and some high quality brands, but where the bulk of the SKUs is packaged in jewel cases, which makes them prohibitively expensive when purchased in large numbers.

Wide Set of Suppliers
We were expecting that a broad inventory would automatically give us a lot of choice in suppliers, in particular for us to be able to get to the suppliers we like, which we have identified are quality suppliers. It turns out that some suppliers specialize in a very small number of brands, such as Verbatim, through which they carry multiple tens of SKUs. While we truly appreciate inventory depth in a given product line, we also need supplier variety. We also saw retailers with a large inventory, but where practically all of the suppliers are low-end media factoring brands, such as Kodak, Maxell, or Memorex. We do not like this pattern either: it is OK to carry a few cheap brands and SKUs, but we also need solid quality suppliers.In order to evaluate how good the inventory was for each store, we tracked 89 media which we felt were representative, and counted, for each store, how many of these media the store had in its inventory. We also specifically counted how many of the quality Blu Ray we selected here for archival grade were carried by the stores we evaluated.

Sorting
When you are going through 100 or more different SKUs, and trying to compare them two by two, looking at speed, price, printability or formats, it is not easy to deal with flat lists of media. When doing comparisons, we quickly found out that the ability to sort results quickly makes a huge difference to identifying the right media (or the lack thereof) efficiently.
A good store will give you access to blank Blu Ray media as category, then allow the user the ability to quickly select by format (BD-R, BD-RE), by capacity (standard or DL), speed, printability, quantity of media in the pack, and manufacturer. It will also allow you to sort your results by price, by best selling order, by most reviews, and by user rating. You would like to be able to see user ratings for the items not only in the product pages, but also in the category listing pages so that you don't have to open every product page to see what rating the SKU has.  An extra-good store will also give you the price per disc unit, on top of the pack price, so that you do not have to use a calculator as you go, comparing unit costs.
This makes 13 different ways to sort, bin or order SKUs, which we counted for each store. We would have liked to be able to sort on unit price (as opposed to SKU price) as well, but did not find a single store that gives you the option. To evaluate how well a store performed, we counted how many types of sorts, among the ones we are looking for, the store could provide us.

Browsing speed
We often needed to view 30 to 40 pages per site, to be able to do good shopping comparisons. We quickly discovered that the speed of the site made a big difference to our shopping experience. The slowest sites could take 3.5 to sometimes 7 seconds to respond, while the speediest ones took little more than the time to reposition your fingers after a click. To get some numerical value of how well a store did, we ran 10 right-click look-ups from the category listing pages exactly consecutively, and timed how long it took for each store.

Price
Clearly, we expect good prices from a good online store. We rated online stores in two ways. For each product in our sample list of 89 SKUs which more than one store had in inventory, we kept track of which store had the lowest price, and how much higher each store's price was compared to the "best" price across the stores we tracked. Then, for each store, we counted how many products matched the best price across all stores, and, on average, how much more expensive they were (as explained above, we excluded products which only one store had in stock). We also kept track, specifically for the 6 media we selected earlier as best archival grade media, of what the store overprice was for the basket of selected media it carried.

Customer service
As we all know, online shopping is fraught with peril, although, by now, our readers buy a majority of their non-food purchases online. Selecting a good online store is a process which must rely heavily on the quality of the retailer's customer service. For this, we used store ratings from ResellerRatings and Google Shopping when they were available. In order to take into account the number of ratings or the lack thereof, we calculated a predictive Customer Support rating by lowering the rating from each by its statistical margin of error, and by averaging the two for each store. Since a low number of reviews will increase the statistical margin of error, this means that stores with few ratings receive a lower predictive CS rating.

User reviews
Nothing can replace user reviews to find out how good the media is - we need to be able to read other users' experiences, in particularly for off brands, and validate both quality and Media IDs, in particular when the media is outsourced. Sites need to provide for user reviews, but they also need to have large numbers of them. This rarely happens when the reviews are hidden in a subtle tab under the product listing. For users to be motivated to write reviews, the reviews need to be highly visible, and be readable on the product page itself. A site with a good number of user reviews has a significant leg up. For each store, we kept track of how many Blu Ray media user reviews were available on the site, if any.


Next we screen Blu Ray online stores... so come back soon!

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Air Filters: Can They Improve Air Flow?

Best Air Filters Review: Air Filter Facts
Air Filter Facts Part 3: Can air filters improve air flow?

In the next few posts, we will investigate if you can improve automotive mileage and performance (i.e. acceleration and torque) by swapping drop-in air filters that have higher air flow. We already know that air flow through an air filter does not impact mileage in modern cars. Because so much opinion on air filters is based on assumptions rather than facts, we should ask - can we measure meaningful differences in air flow between air filters?

Air flow differences across air filters

Fueleconomy.gov  is a federal government site focused on - guess what - fuel economy.  Under their aegis, the famed Oak Ridge National Laboratory published, in February 2009, a research report investigating the effect of air filter condition (i.e. air flow restriction) on fuel economy. The researchers experimented with both modern fuel-injected engines, and with older carbureted engines. They showed conclusively that some aftermarket (high flow) filters were able to provide more air flow than OEM filters, measuring a lower pressure loss across aftermarket filters than OEM filters:

 

These tests were done on the vehicle itself, at wide open throttle for 10 seconds. There is a clear difference  between no filter, high flow aftermarket filters, and the OEM style filter, which experiences the highest pressure drop (meaning the least air flow, but also, probably, the best filtration). So, clearly, it is possible to increase air flow (and decrease pressure drop) by using a different drop-in filters. We will see later than the K&N filter is particularly successful at that. However, the differences, when compared to atmospheric pressures, are very small - so it is not clear if these will result in actual changes in mileage or performance. 

Conclusion

• Non-stock air filters can improve air flow

How much worse does air flow get when your air filter gets dirty? Is there a measurable difference? Next we discuss the impact of dirty air filters on air flow... So come back soon!

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Car Air Filters: What To Look For

Best Air Filters Review: Air Filter Facts
Air Filter Facts Part 2: What makes for the best air filter

What makes for a good automotive air filter? To a degree, it depends upon your usage. Rural drivers in a very dusty environment will look carefully at capacity, while Friday night racing aficionados will look more at air flow. We look at criteria for an average user, who does not race, and whose environment is only moderately dusty. For our average user, we present below the most significant criteria for air filters, by decreasing order of importance.

Filtration efficiency

We already discussed here the importance of filtration, which simply cannot be overemphasized, as dust is the primary cause of engine wear: both oil and air filtration are the most critical factors to making an engine last.  Lycoming, the manufacturer of aircraft engine, states in its maintenance manual: "Dust or some form of dirt is frequently the principal factor in premature piston ring, ring groove and cylinder wear. If a worn or poorly fit air filter allows as much as a tablespoon of abrasive dirt material into the cylinders, it will cause wear to the extent that an overhaul will  be required. Evidence of dust or other dirt material in the induction system beyond the air filter is indicative of inadequate filter care or a damaged filter." The difference between filtration efficiency of 90%, 99%, and 99.9% is very significant:

The average capacity of all the filters surveyed in our series is 234 grams. If we assume that the life cycle of the filter is approximately 40% of its capacity (you will change it before it gets clogged), we can assume that the filter will see roughly 100 grams of dust at the intake. If the filter has 90% cumulative efficiency, what will pass through it is the amount of the first jar. If it has 99% efficiency, it will pass through the content of the second jar. With 99.9% efficiency, it will pass through the content of the third jar. Given that whatever passes through the engine goes straight into the cylinder chambers, which one would you like it to be for your car?

It is worth noting that the typical way to measure filtration efficiency is by calculating how much dust is filtered over the theoretical lifetime of the filter (i.e. until it reaches capacity), which is really measuring cumulative filtration efficiency. Why is this important? Filters get more efficient as they start accumulating dust. This means that, if you always use clean filters, your efficiency will be lower than that measured in ISO 5011 filtration tests! Amazingly, is actually better, for filtration, to have some dust in your filter. What this means is that, unless you keep your filters until they clog, your true filtration efficiency will be lower than that measured for your air filter.

We should mention, in passing, that we have frequently seen manufacturers' specs for filtration efficiency be proved wrong by third party tests. Unfortunately, it appears that we cannot trust air filter manufacturers to give us their own filters' specs unless the actual tests are conducted by third parties.

Fit

This is a frequently neglected factor. The variety of shapes and sizes across all cars is very, very broad, and there are many cases when a filter brand which performs in general well does not have perfect fit for a given car's intake. Big air filter manufacturers, such as Wix or Purolator, will often design and manufacture filters themselves for vehicles with wide distribution, but may sometimes factor out filters for less common vehicles, making fit and quality problems more likely.

As a result, it is not possible to evaluate fit on the basis of the air filter brand, since it varies by vehicle. If you are not going to actually check out the fit yourself, you are better off requesting an OEM filter for your vehicle, which is more likely to have good fit.

Capacity

The capacity of an air filter is the amount of dust that it takes to increase the resistance of the filter to air flow by 10" H2O, and is supposed to be a good measure of what it takes to clog a filter. The larger the capacity, the longer you can take before you change your air filter. Of course, larger capacity is also preferable when driving in a dusty environment, where a lot of dust may end up in your filter in a short amount of time. While we do not believe that 20-30% difference in capacity makes much of a difference to the average user, we found out that filter capacity varies by a factor of 1 to 10. We do believe that a difference of one order of magnitude makes a significant difference.

Build quality

There are many ways to build a cheaper air filter - but how much do then also cheapen build quality? What material is the frame made of? How well dimensioned is it? What is the filtration medium? How are the pleats built? A better-built filter is likely to be more expensive, although not always better performing. Given that air filters can last through tens of thousands of miles (while oil filters only last thousands of miles), some difference in price may not be significant to the overall life cycle cost of your vehicle, while filtration improvement definitely will make a difference.

Quality control

The best filter does not amount to much is quality varies enough between units that fit is not guaranteed, or that filtration is not maintained. As air filters have become commoditized, quality control and build quality have become progressively worse.

Air flow

It is the last criterion on our list, and the most controversial as well. It is the least important of all criteria, and we will discuss why. The next few sections will investigate the influence of air flow on mileage and on performance.


Next we discuss if different air filters can impact air flow... So come back soon!

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