When browsing the web I found some interesting sites on oil filters. I learned that they vary a lot in quality, and many are the same things marketed under a different name. First I saw a good site that compared filers for Ford 5.0L cars and this one for Preludes. Originally I thought that my Toyota filter would be one of the best of the general brands cus they wanted their cars to last. But then I tore it apart, and compared it to the numbers from that web site. Even after adjusting for the differences in size I found the Toyota still on the bottom of the list. Then I found another site that did quantitative tests on filtration, and the Toyota filter performed deplorably. So I decided to get a variety of filters made for my car and do a more fair comparison. I am able to take a variety of measurements on each filter but I am not able to do actual oil flow and particle filtration tests which is the real measure of any filter. So consider these numbers a starting point to base your decision on. If you don't see a filter you are interested in you can send it to me and I will tear it apart and add it. Be aware that filter construction may change, like the MR2 data was from 1995, so depending on when you are reading this it may no longer be valid, but I hope it is helpful.

Description Type Material Folds Thick(cm) Width(cm) Length(cm) Area(cm2)
Purolator PureOne
(PL10241)		 1 Micronic 63 0.085 5.8 147.5 855.5
Toyota USA
(08922-02011)		 1   53 0.095 5.8 124.0 719.2
Fram Extra Guard
(PH3614)		 2 Synthetic glass & cellulose 41 0.090 5.8 118.0 684.4
Penzoil
(PZ-21)		 2   40 0.085 5.8 114.5 664.1
ACDelco Ultraguard Gold
(UPF53)		 3 Synthetic fibers 36 0.050 5.7 95.4 543.8
STP
(S3614) 		3   61 0.070 5.8 153.7 891.5
Bosch
(3330)		 3 FILTECH 55 0.085 5.7 135.8 774.1
Mobil 1
(M1-102)		 3 Synthetic fibers 54 0.095 5.7 132.8 757.0
K&N
(HP-1002)		 3 Resin impregnated filter media 61 0.065 .5.7 153.3 873.8
Toyota Japan
(08922-02004)		 4   84 0.090 5.5 217.8 1197.9


There were basically 4 different designs. The one from Toyota made in Japan was the only one that had the filter folded in a flower pattern rather than a star pattern so they were able to fit much more material in their filter. The 'Type 1' filters have 7 rounded-rectangle holes on the bottom with the long axis along the circumference and the numbers '3', '4', and '16' stamped on the bottom. The 'Type 2' filters can be identified as bottom has 8 holes that are elliptical and equal size with the longer axis on the radius from the center. The 'Type 3' filter bottom has 8 or 6 holes that are round, and the bottom is a smooth shape with one hole being bigger than the others, all have 'AA' stamped on them. Type 4 is the filter from Japan and I don't have enough to tell what features they have in common. You can get more details on the internals of these filters at the Mini-Mopar and Prelude oil-filter sites I mentioned before. While the internal construction seemed to be shared, the quality and quantity of the filter paper was quite different. There are numbers for the different filters for how efficiently they filter but the tests are run by the manufacturer so I am not sure how you should interpret them, and they are just a general number not for the one specific to our car.

Description
SAE J806
SAE J1858
Single Pass Multi Pass Single Pass
Purolator PureOne
()		 99.7% 96% 86.1%
Toyota USA
()		      
Fram Extra Guard
()		 96.2%    
Penzoil
()		 94%    
ACDelco Ultraguard Gold
()		      
STP
()		      
Bosch
()		 98% 93%  
Mobil 1
(M1-301)		 98% 95%  
K&N
()		      
Toyota Japan
()