I have a briggs 18 hp, I go to walmart and get the Supertech 3614 filters I believe, they run me like $2 something a pop, piss on paying $12 for a genuine briggs filter. I find this filter is only in stock at walmart about half the time, when they are in stock I pick up 4 or 5 at a time, oil and filter changes every 50 hrs keep my oil looking great even when it is time for a changing, also this filter is the same as the long briggs filter so you get a small amount more oil compacity, I find it rediculous an air cooled engine like this only holds 1.5 qts with the filter, I have been tempted to drill and tap the oil filter holder and install a remote setup that holds 2 giant filters that would fit a big block chevy. oh well a new motor is only a grand, so when it blows 2k hours from now I will just slap in a 20 hp instead