Have two Mobil1 M1-204A filters that are different - which is better?

[92saturnsl2]

I picked up a couple of these filters at a local bargain outlet for about $5 each. They had many more but my filter stash can't accommodate any more at the moment.

When I got home I looked at the oil filters closely and noticed that although both filters are the same M1-204A, internally they are different. Both appear to be made by Champ Labs (one inlet hole is larger than the rest) but one has a bypass valve on the top of filter (I see a blue plastic cap up there) and the other has the bypass at the base of the filter, I see a large coil spring at the bottom and no blue cap up top.

If one were to choose between the two, which is better and why?

These are the filters, both boxes are 100% identical.

 

[blupupher]

Thread end bypass tends to be more favored on filters that are mounted thread end up.
Thread end seems to be falling out of favor now days, Wix and a few (very few) Purolator made filters.
No idea how a Champ made thread end bypass came about, wonder if this is new?

 

[shibby6600]

I think OP's definition of base is the bottom of the filter, not the base plate with the threads. One has a plastic hook style valve and spring with a stamped retaining spring, the other has an internal coil spring valve and coil retaining spring.

I have not seem evidence that one is superior to another. I would use both.

I will mention, however, the M1 filters with stamped retaining springs do not always have a sealing surface on the bottom end cap except for metal to metal pressure from the retaining spring. Unlike the Fram ultra series that has an actual gasket to seal the retaining spring to the filter end cap.

 

[Pinoak]

I'd choose the thread end bypass. It's just a much smarter design.

 

[bullwinkle]

I'd choose the dome end bypass, the filter will have more media! Honestly, use them both! If the engine is sludged, use the thread end first & the dome end second.

 

[BlueOvalFitter]

Originally Posted by Pinoak
I'd choose the thread end bypass. It's just a much smarter design.

+1