The Nissan owners club, NICO, helped sponsor a test of original equipment air filters, vs stock air filters, including oil washed filters, such as the K&N. Needless to say, the aftermarket filters came in a poor last place to the original equipment filters. The testing was conducted by the machine's manufacturer, at the factory's test facility. But, don't take my word for it, READ it for yourself.
Here is another air filtration test, done in a real life situation, not in a lab.
Before you ever consider using an aftermarket filter on your BMW motorcycle, please read this article: Oil Filter Study
For what it's worth, I have several BMW branded filterd, in the BMW box, and they all appear to be made by Champion.
Before you ever consider using a Fram filter, read this email from an Allied Signals production engineer.
Here's an interesting review of filters to fit one particular model of Suzuki, by Mark Lawrence.
Here's a good article about the way filters work, by Mark Lawrence.
Here's a extensive cross reference of oil filers for many brands of motorcycles, by Mark Lawrence.
Here's a recap of oil filter tests done by a Finnish car magazine. Note that the article was published in 1995, so the results might not be up to date.
By the way, I spent many hours researching oil filter aricles, and more than 50% of them say to avoid Fram filters.
A special wrench is needed to remove many BMW oil filters. Aside from the BMW item, several other manufacturers make similar wrenches. Lisle part #547660, for about $8, is available at some auto parts stores. But any 76mm X 14 flute wrench should work.
If you have an interesting source for parts, contact the webmaster at email@example.com
Note: While all or most of these filters will work, many of them have a different number of flutes on the end of the filter body to engage
the filter wrench.
Warning: Avoid any filter which has the non-slip grip on the case. The non-slip grip is basically pumice in a rubber binder. Pumice is extremely abrasive, and not something you want in your oil.
AC DELCO: PF-53, PF1127
Bosch 3330, 72161
Hastings 157A, LF157
Motorcraft: FL-271, FL-793
Napa Gold 3012
Purolator L10241, FCO-201, PER-241
Wal Mart Super Tec ST3614
WIX 51348, 51785
Here's a list of fuel filters to fit K bikes. The Mahle Knecht listed below
is the genuine BMW one... if you can find it...
This list was compiled by Motoeddie, of Philadelphia. Thanks, Eddie.
BMW - 16 14 2 325 859
KNECHT MAHLE KL145
Napa Gold 3032
Purolator - F20011
Here is a link to a Wix list of all 'vehicles' using this particular Wix filter.
Note that the Autozone ff424 now appears to be made of plastic. Avoid this and any other plastic filter.