Oil Filter - Larger Size?

[Hardin Thicke]

I was in my dealership purchasing a case of filters, when I commented on how small the PF48 filter was for the size of the engine. The parts guy went away, came back and dropped a PF61 filter on the counter. "I didn't give this to you, but this one is bigger and is the exact diameter, and thread size." I purchased 2 of them to try out. The correct filter, the PF48 has a spring at the bottom of the can while the PF61 does not. I believe this is the anti drainback valve. My thinking is that since the filter is vertically mounted, the drain-back valve is not needed. Any comments or advice?

 

[Hardin Thicke]

Answering my own question. So much for parts guys. The PF61 is not interchangable because it uses Imperial threads. The correct filter, PF48 uses Metric threads.

PF48: Thread Size: 22X1.5 MM
PF61: Thread Size: 13/16-16

Back they go.....

 

[Black Dog]

They say that the new small one is better, yes the anti drainback valve, which may or may not matter, but also that it "somehow" has better filtering ability, same or more surface area, or better media, or something like that. Forgot exactly what I read and where, but the idea was compact design with no sacrifice in ability. Personally I have a hard time accepting that too, all I know is if you ever blow the motor (albeit unrelated to the filter) it better have the correct recommended filter size/design. I think what the parts guy meant was "if anything ever goes wrong, don't point at me!" Truly he is both a genius and a pal.

 

[Black Dog]

And I think that PF48 has been the main V block filter for longer than I've been around, if nothing else I wouldn't think it to be a cutting edge design or anything. But for now I can only assume that the new one is, I want to cut them open.