Originally posted by HC
One thing seldom mentioned in bypass filter discussions is pros and cons of the different styles. My spin:
GCF, Frantz - They work, cheapest element replacement, but more frequent service interval
This isn't correct--GCF sells *three* sizes of bypass filters, the O-1, the O-2, and the O-1 Jr. The O-1 Jr. is the small one that takes a roll of TP and requires an element change somewhere between 2,000 and 5,000 miles (depending on your goals). The O-1 Jr. costs about $165.
The O-1 is much bigger and takes a roll of paper towels. Due to its large size, it also increases your engine's lube oil capacity by *six* quarts. This one needs an element change every 10,000 to 20,000 miles, and costs about $400.
The O-2 is *really* big and is way overkill for our engines. Like the model number implies, it's twice the size of the O-1 and takes two paper towel rolls. Put one of these puppies on and your oil system now takes 24 quarts of oil! That, in addition to getting good bypass filtration. The O-2 appears to be about $550.
I realize I'm kind of ranting when I say this (and it's NOT aimed at anyone in particular), but EVERY thread I've ever read on the TDR contains the same bad information--that GCF only makes one bypass filter, that it's insanely expensive, and that you have to service the thing all the time.

I have no idea where this comes from--one look at the price page tells you that there are three sizes of engine oil filters and that they're completely different.
I don't yet have a bypass filter on my truck, but I've already decided that when I do, it'll be a GCF O-1.
Oh, and one thing to keep in mind to put this all into perspective--every million-mile Dodge Ram with a Cummins that I've ever read about has never made any changes to the stock oil system. Nothing but good oil and filters, and regular service intervals.
Mike