TL; DR I'm looking at a late 70's diesel Ford tractor tomorrow that has an air bath oil filter. I'm surprised something this new has such a primitive setup. Additional reading if you like tractors: Dad and I are looking at a Ford tractor tomorrow. Japanese made late 70's early 80's. 4WD, gear drive, ag tires and diesel. For those of you who know about my great grandfathers Wheel Horse that I have, this Ford belonged to him as well. I of course had to look it up and it has an air bath oil filter. I'm somewhat surprised something this new has such a primitive setup. I know nothing about vintage tractors so perhaps it's not as abnormal as I think it is. Either way, it doesn't sound efficient. The only thing I have to compare it to is my Kubota garden tractors that are of the early to mid 80's to late 80's vintage. They use spin on filters. My neighbor growing up had an old mid 30's international B that he did a filter conversion on so he could use a 3/4-16 thread filter so perhaps the same could be done here. No idea at the moment.