I don’t know who make the Perkins branded oil filtres, so cannot judge if Fram’s are truly “equal” (quality), but Fram do have the ByPass.
See also this opinion, excerpted from ➥ Oil filters - Mechanical Database
Fram Extra Guard
Years ago Fram was a quality filter manufacturer. Now their standard filter (the radioactive-orange cans) is one of the worst out there. It features cardboard end caps for the filter element that are glued in place. The rubber anti-drainback valve seals
against the cardboard and frequently leaks
, causing dirty oil to drain back into the pan. The bypass valves are plastic and are sometimes not molded correctly, which allows them to leak all the time. The stamped-metal threaded end is weakly constructed and it has smaller and fewer oil inlet holes, which may restrict flow. I had one of these filters fail in my previous car. The filter element collapsed and bits of filter and glue were circulating through my system. The oil passage
to the head
became blocked and the head
got so hot from oil starvation that it actually melted the vacuum lines connected to it as well as the wires near it.
Fram Double Guard
Another bad filter idea brought to you by your friends at Fram. The filter itself is a slightly improved design over the Fram Extra Guard, but still uses the same filter element. It has a silicone anti-drainback valve, a quality pressure relief valve, and enough inlet holes for good flow. The big problem is that they are trying to cash in on the Slick 50 craze. They impregnate the filter element with bits of Teflon like that found in Slick 50. As with Slick 50, Teflon is a solid and does not belong in an engine
. It cannot get into the parts of the engine that oil can and therefore does nothing. Also, as the filter gets dirty, it ends up filtering the Teflon right out. DuPont (the manufacturer of Teflon) does not recommend Teflon for use in internal combustion engines. Please do not waste your money
on this filter.
Fram High Mileage
Yet another bad filter idea brought to you by your friends at Fram! Gotta love these guys. It's a Fram Extra Guard with a weird goo cartridge suspended on the clean side of the filter, blocking the outlet. It's supposed to be some kind of additive package, but if you want a high mileage oil, buy a high mileage oil. I don't trust these guys...sorry.
Fram Tough Guard
Even with all the problems of the other Fram filters, this one is not too bad
. It has a heavier filter element with more surface area, a silicone anti-drainback valve, the cheap
pressure relief valve, but with an integral screen
to keep out large particles, and enough inlet holes for good flow. The only other drawback to this filter is that it is capped on each end with cardboard instead of metal. Looking in through the center outlet does not reveal any paper end caps, but they are there. I personally do not use this filter, but the design didn't have enough bad qualities to cause me to tell others to avoid it.
If you look into the center hole all the way to the top of the filter, you will see a kind of "button" in the end cap of the cartridge (which looks like it's made of metal from there). This is the plastic bypass valve, on the Fram “Tough Guard” oil filtre.