Sorry guys, I'm not impressed. A 95% efficiency rating at 20 microns is a beta ratio of 20.
http://www.machinerylubrication.com/Read/564/filter-beta-ratios
Each step up on the beta ratio chart, the number of particles downstream is ONE HALF the previous step. Put in real numbers, a 95% efficiency at 20 microns allows 100,000 particles upstream and 5,000 downstream (AFTER the filter).
Realize this IS the Quaker State $2 filter we're discussing.
So why would anyone in their right mind pay $8-10 or more for a filter?
Well, a Fram Ultra, which retails at autozone for $9.99
http://www.autozone.com/external-engine/oil-filter/fram-ultra-oil-filter/269851_0_0/
Has an efficiency rating of 99% at the same micron size as our $2 filter...99% is a beta ratio of 100 vs 20. Since our downstream particle numbers are cut in half from a beta of 20 to 40 to 60 to 75 to 100, that means our high dollar $10 Fram offers 5 times the filtration; and I guess, coincidentally, it just happens to be 5 times the price.
And an Amsoil filter is 98.7% at 20 microns, I think it is about $14, also rated for 15,000 miles, and it is 3 steps up the beta chart from 95%, so you need 5 filters good for 3K to match the value here...
And just what micron size particles do you want between your piston rings and cylinder walls; crankshaft and bearings, between the cam lobes and lifters, between the timing chain and gears, etc.?
Please take this in good humor and not personally, but since someone mentioned "manufatured to spec" by Purolater, can anyone tell me what OEM specs for micron ratings at what efficiency are for Ford, GM, Chrysler, Honda, Lexus, BMW or ANY auto manufacturer? Please post links and educate me.
I'm fine if you're happy with a 95% filter at 20 microns (beta 20). I don't care if you put on an aluminum block off plate and run without a filter. The higher the beta ratio, the better the filter, as long as it is also rated for a decent change interval and has a capacity worth discussing.
I run an NTZ AL09 bypass with a beta ratio of 2000, it is 99.97% at 2 microns, so my filter is 100 times better than the $2 bargain; and it is rated for 30,000 miles. http://www.ntzfilter.com/popup/slide26.asp Right now I'm going on 16K on my oil and it is 8 times cleaner than my baseline virgin new oil sample I ran. I just pulled this filter from between my right and left hip pockets.
Sorry if I seem a little sarcastic toward Quaker State, maybe I'm just an OCD filter snob. Don't take me too serious. Do whatever lets you sleep at night.
And yes, I can be a hoot at parties...Just not impressed with an "OEM spec" filter. I would humbly and politely ask my fellow BITOGERS not to be offended with me; yes, I see answers to this Q all over the board. I'm sure there are fellows out there that have run $2 filters (and changed them) for 50-80-100K. Me? I just can't sleep at night with dirty oil, and I really DO hate to change oil.