Kohler 12 050 01 oil filter substitutes: Fram PH3614, Supertech ST3614, Motorcraft FL-910-S, Purolator L10241. These have essentially the same size rubber gasket, same diameter body, same height, and have the same 3/4-16 thread. The 12 050 01 filter is used on 18hp Kohler Courage SV471-SV601 & SV541 and others. The Fram PH3614 is also used on 2003 Toyota Tacoma 3.4 liter V6 engine, which may help you find other substitutes. The substitutes have worked fine for me and I see no reason to pay more for the Kohler oil filter. I can buy three Supertechs for the price of one Kohler. I change oil and filter at beginning of the season, when the oil has about 100 hours on it from previous season.

As someone who has worked for 6 years at NAPA as well as independent auto parts stores and have had long, candid conversations with petrochemists and sales representatives from Honeywell (FRAM/Defense/Canadian Tire/Pennzoil), Dana (WIX/NAPA/Kralinator/Delco) and ArvinMeritor (Arvin/Purolator/G.A.P.,), I can tell you that there is NO difference whatsoever as far as the internals of OEM-replacement filters. With regard to specialty filters like Fram Racing, Purolator PureOne, etc., there is a difference. Think of this from the company's perspective. Oil filters must meet or exceed OEM requirements of the vehicles for which the manufacturer recommends. In the case of WIX/NAPA Gold, the silicone-rubber anti-drainback valve is superior to the nitrile rubber valve on the Kralinator/NAPA ProSelect/Silver, but the OEM requirement is only for a nitrile rubber valve. In everyday use with oil changes done at intervals of less than 10,000km, both valves function perfectly. The silicone-rubber valve is made orange in colour to look pretty and make you think you're actually paying for something when in reality, you're paying for overkill. In the case of FRAM, the Defense filters are listed as a second line at a lower cost but have the exact same warranty as the RAM filters. The only difference between the two is paint, marketing and the "easy-grip" is not found on the Defense, Pennzoil or Canadian Tire filters. Think about this from a corporate perspective. If you were making two lines of filters, would you go through the time and expense of stopping the line and retooling just to make an inferior product or would you just do one production run, paint and market them differently and save the time and money? I think we know the answer. It wouldn't make good business sense to stop production because it would cost the company more money to make a product with a narrower profit margin. This is why you NEVER see comparisons of Fram vs. Defense or NAPA Gold vs. NAPA Silver/ProSelect/NASCAR. If they ever did a test like that and published it, nobody would ever buy first-line filters again. The other side of this racket is the oil itself. There are mechanics who swear by Pennzoil, mechanics who swear by Valvoline, mechanics who swear by Quaker State, Castrol, Havoline, Mobil, etc. Either the vast majority of mechanics are automotive morons or they just respond differently to the different marketing strategies of the oil companies. Consumer Reports once did a test of 75 different brands of oil, this test included synthetics, semi-synthetics, virgin conventional and re-refined conventional. They put these oils into the toughest street-legal test imaginable for oils, New York City Taxicabs. The cabs were driven day and night in stop and go traffic with the oil changed every 10,000km (6,000 miles) instead of the recommended 5,000km/3,000 miles in order to get worst-case scenario results. After 100,000km/60,000 miles the taxis were pulled off of the road and the engines were taken apart to test the wear levels on vital engine parts. Their result that the range of wear levels across all 75 brands and types from what could be called the best to what could be called the worst was thinner than a thin, glossy magazine page. They also concluded that no oil brand or type consistently produced more or less sludge or varnish than any other. Their final recommendation: Change your oil at regular intervals and use whatever grade of conventional oil your manufacturer recommends. Regardless of their claims, no oil (conventional or synthetic) will make your engine live longer than the cheapest oil on the shelf. My 1993 Honda Civic that went 300,000km before I burnt a valve which was more a result of towing a U-Haul twice the car's size for 8 hours through mountainous terrain. Even then, the engine still lived for 6 months. I always used the cheapest oil and filters I could get my hands on simply because I had the inside information. Next time you go to a shop, look at the oil and filters in their bays. I guarantee you that you won't see any specialty filters and you'll see the least expensive oils that meet OEM requirements. This is the reason that all those Castrol Syntec and Mobil 1 commercials never compare themselves against other synthetics, only conventionals. It's because their "torture tests" that break conventionals down and not synthetics are more brutal than what oil goes through in a Formula 1 Grand Prix Race! I'm pretty sure that we're all safe in the knowledge that not only will we NEVER drive at 200mph, our engines are not even CAPABLE of imposing that level of stress on oil without destroying themselves in the process! LOL Here is a link that might be useful: Synopsis of Consumer Reports Oil Test

"Briggs/Kohler type" 3/4" X 16 threads 8-11 PSI Bypass Gasket 2.734"OD X2 .430"ID 0.226" thick Length" Wix Purolator Hastings Kohler B&S Baldwin MotorCraft AC 2.3" 57035 NA LF503 2805001 492932 B7165 NA NA? 2.7" 51056 L35310 LF302 1205001 492056 B1410 NA PF2210 3.4" 51348 L10241 LF157 5205002 491056 BT223 FL793 PF53 4.8" 51516 L20195 LF134 NA NA B243 FL400A PFL400A WIX makes NAPA Gold and CarQuest Blue filters. (identical except for the paint job) For a NAPA filter, use the last 4 digits of the Wix# For a CarQuest filter, replace the first 2 digits of the Wix# with 85 Example. Wix 51348 becomes CarQuest 85348 or NAPA Gold 1348

The oil filter question has been debated and will continue till the world ends. It's really up to each person to decide. Oil changes at recommended intervals seems more important than the filter one uses and I choose to use OEM filters cause I've found they are not much more expensive than quality third party filters. Here's a pretty definitive review from someone who knows what he's doing... http://www.gmtruckcentral.com/articles/oilfilterstudy.html