I waffle on this subject. I believe you get what you pay for basically, but sometimes this may or not be 100% true. At this point, after a lot of investigation, I would say that I think the Mobil 1 filter, followed closely by the K&N, are the state-of-the-art.

Recently, I looked over a filter from SuperTech. Yep! Wal Mart's house brand. I know it's a Champion Labs filter, that I suspect is also sold under the Bosch label. Right down to the black canister. One could do worse. Especially for...$1.97!!!

Comments welcomed...

I have cut open more than a dozen filters that claim to be identical. www.widman.biz/Aplicaciones/Filters/filters.html
We don't get much choice down here, especially since we get cars manufactured in dozens of different countries to dozens of specs. I stay away from FRAM, whether US or Brazilian, since they do not seal at all. Any I suspect I cut open. That being said, some of the cheapest ones we get are DENSO. They look good inside and out, although not as much media, and they are what several of the manufacturers (including Toyota) use.

Just curious if you have any experience with Purolator, they are quite common here in India although with the proliferation of Japanese vehicles currently Denso too is becoming common. Purlators are made quite close to where I live.

Here in the USA, Purolator filters are very good. My preference is Motorcraft (said to be manufactured by Purolator) though for the bypass valve being in the threaded end. The L40017 Purolator Premium Plus, however, does have the bypass in the threaded end. L40017 is a Motorcraft FL299 (longer version of FL-1A).

As everyone else has I have done some investigation of automobile oil filters as well and assuming that there is "truth in advertising" the Wal-Mart filter has the biggest bang for the buck ($1.97) followed by the Fram Toughguard at ($4.96) both filters are rated at 98.6% efficient at the 20 micron size according to the ISO 16889 test method (multi- pass efficiency). If I am not mistaken that is a higher efficiency rating than the Mobil 1 (96%) or the K & N filter at more than 3 to 6 times the cost (local price for these filters are in the $12 to $14 dollar range.) I don't know if people buy on price alone or if name recognition also playes A part, but for me I typically buy on performance. Check it out the next time your around the oil and filter section of any store.

Here is an interesting study:

http://www.oilfilterstudy.com/

My filter preferences are Motorcraft, Purolator Premium Plus, and Wix

My favorite filter is a rebuildable unit by CM Filters. This unit has machined aluminum body, uses Viton seals and has a synthetic media that filters down to 8 microns. It is enclosed in a steel cage to which I have attached two Neodymium magnets. I pull it off every 5 years to replace the seals. Compared to the normal disposable filter, there is nothing to guess about. I know I'm getting the best flow rate and the best filtration.

This message has been edited. Last edited by: Houckster,