As you probably know, Honda doesn't make filters. They just have filters made to their specs and get their name put on them.

My thoughts on this topic have always been this. If a Fram or Purolator filter is good enough to protect a V-8 engine for 5000 miles, then it's certainly good enough to protect a twin cylinder engine that has a displacement around 12 percent of the V-8.

I know lots of people on other forums who use automobile oil filters on their lawn/garden tractors and have done so for many, many years without any problems. Also, I have yet to read anything that would show using these filters to be a mistake.

Next time you remove a OEM Honda filter, let it drain for a week or so and then carefully cut it open so that you can see the construction of it. When you're done with the Purolator filter, do the same thing and make a comparison on how much element (square inches) is in each one. I would think that the micron rating would be the same so to me, the big difference would lie in how much element was their to catch contaminants.

I've been using a WIX filter on a Vangard for 10 years. In fact it's the same filter my 1989 Toyota pickup uses. The truck has over 1,000,000 miles. I have no idea how many hours the mower has? The WIX is larger (longer) than the BS filter! The WIX has an anti-drainback valve keeping oil in the filter for oil wet starts. Does it help? Well it ain't hurt any! Clean oil is the least of my problems!

I was not concerned so much about the filtering ability of the car oil filters as I was with some structural design difference, such as pressure or flow characteristics. Will the small engine allow the filter to work properly compared to being on a large car engine?

Absolutely.

Most engines work at oil pressures ranging from 15 PSI to 80 PSI whether they're water-cooled, oil cooled or air cooled, single, twin, triple, quad, five, six, eight, ten, twelve or sixteen cylinders. The GPM rating of a small air or water cooled engine in a piece of outdoor power equipment is small compared to any auto engine. Therefore, if a filter will handle the GPM and pressures put out by a 350 cubic inch Chev engine, then it will most certainly handle the GPM and pressures put out by oil pump in any Honda, Kawasaki, Yamaha, Kubota, Linamar, Onan, Kohler, Briggs etc engine that has pressurized lubrication.

In other words, set your fears aside and go buy the four buck car filter. It will work just fine.

Put your concerns to rest. So long as you have sufficient space for the filter to mount up without chafing or rubbing any part of the machine (that could damage the filter body) you will be OK. As pointed out above, having an "anti-drain back" valve (check valve) incorporated into the filter is important. I personally think it is also important that the filter media be of a "waterproof" material (and Wix, to name one, uses waterproof media). ALL internal combustion engines produce water as a byproduct of the combustion process. During "cold start up", a significant volume of this water gets past the piston rings and into the crankcase where it becomes entrained into the lube oil. Usually this is a "temporary" condition as the water is later evaporated back out of the oil as the temperature of the engine and lube oil rises higher than the point where liquid water can exist. This phenomenon does not normally have any effect on filter media that is NOT WATERPROOF, especially in air cooled engines (because of their characteristic higher operating temps), as the water in the oil never remains there long enough to soften or weaken the filter media to the point of "matting over". Cold engines that are started up and shut back down without the engine ever reaching operating temperature are the ones most likely to suffer from water induced filter degradation (or failure). Liquid cooled engines that have a defective head gasket can have water contaminated oil before the complete failure of the gasket makes the defect apparent "otherwise". Liquid cooled engines that are operated with the thermostat removed (or stuck open) will also suffer more from this type of degradation because the engine "runs too cold" for longer time before heating up enough to evaporate the water from the oil. "Matting" of the filter media occurs if the (non waterproof) fibers of the filter lose some of their "structural strength" due to becoming pliable when they absorb water. As the fibers settle (pack down) on top of one another, or swell up in diameter, the filtration rating will increase (catch smaller debris) temporarily. It is "temporary" because once it gets "matted", it can no longer flow the same volume of fluid it was intended to. As the matting effect increase, the filter bypass valve will unseat, allowing some unfiltered oil to "bypass" the filter media altogether. A matted filter might bypass oil during a cold start up due the the inability of the media to flow the viscous, cold oil, and then resume filtering the oil once the oil warms and "thins out". Matting can also lead to tearing or rupturing of the filter media, which then allows some of the trapped debris, and sometimes, bits of the filter media, to be transported out of the filter and into the very engine components that are are supposed to be protected by the filter. Oil filter manufacturers (that use non-waterproof media in their oil filters) hide behind the disclaimer "it's an oil filter, not a water filter" to defend their choice of materials, and (hopefully) for most folks, the fine detail of "waterproof versus non waterproof" media will never become an issue.

Be sure to use OEM filters during the warranty period, Briggs for one is quite sticky about it.

Thanks for all the information. If I asked the Simplicity dealer, he would probably have a different opinion about non-OEM filters. It's not in his best interest to tell me "sure, go buy the cheap oil filters, they are just as good". There must be a BIG markup on these items. Since I change the oil and filter at the end of each mowing season, I'll be glad to save some money.