Dear Tom and Ray:

I am the proud owner of a 1987 Ford Crown Victoria which is approaching 200,000 miles. In the four years since I've purchased it, I've never changed the oil. I am using a Frantz Oil Filter in addition to the regular spin-on filter that is standard equipment. The Frantz Filter is a canister that gets filled with a roll of toilet paper every four thousand miles. Every time I change the toilet paper, I add a quart of oil. I have been using this filtering system since 1964 on all of my cars, and have never changed the oil in any of them, nor have I ever had an engine problem other than minor tune ups and such. The reason I'm writing is that I'm not an engineer, and would like to know if it's just plain luck that I'm having, or is there really some merit to this type of filtering system?
Leo

TOM: We don't really know, Leo. Our evidence is all anecdotal; just folks like you telling us about their own experiences. But everyone who's told us about this filter has said the same thing you have...that they're great.

RAY: But who really knows? There are other factors that could contribute to your "luck." The fact that you've gone 200,000 miles so quickly means you've probably done an awful lot of highway driving. We know that highway driving is easier on cars than city driving, so that probably has something to do with it.

TOM: Plus, people like you--people who would take the time to install something like this, and wrap a band around their filter every four months that says "sanitized for your protection"--obviously care a lot about their cars and probably take good care of them in other ways. So that may be a factor in the "luck," too.

RAY: I suppose if research ever shows that these filters are as great as their proponents say they are, the big three car companies will move to adopt them.

TOM: So watch the Wall Street Journal, Leo. When you see GM make a move for Charmin, you'll know the evidence is in 1984.