What puts the "marvel" in Marvel Mystery Oil?

Dear Car Talk

Dear Car Talk | Jun 01, 1999

Dear Tom and Ray:

My dad, who knew more about cars and engines that anyone I ever knew, swore by the benefits of Marvel Mystery Oil. He always poured MMO in the crankcase at each
oil change and sometimes put it in the gas tank. His cars always made it to 200,000 miles. Will Marvel Mystery Oil harm a modern engine? My 1997 Ford Ranger has
developed an occasional noisy lifter problem that the dealer can't replicate. Harking back to my dad's experience, I'm tempted to dump a can of MMO in the tank and
crankcase, but one of the dealer's mechanics said he wouldn't do it because the factory recommends against additives. There's nothing in the manual about additives.
What do you think? -- Les

RAY: Marvel Mystery Oil is kind of like chicken soup, Les. It probably won't help, but it can't hurt.

TOM: The reason most manufacturers make a blanket recommendation against additives is because there are too many to keep track of. There are thousands of additives
on the market these days. Several of them probably even contain chicken soup.

RAY: Most of them, like MMO, probably won't hurt your car, but it's impossible for the manufacturers to test them all. So they play it safe and don't recommend any of

TOM: And I doubt the MMO will solve your lifter problem, which could be caused by low oil pressure. So have your oil pressure tested. The lifter could also be leaking
down, which is common these days with self-adjusting lifters. A lot of them are just not "beefy" enough by design, in my opinion.

RAY: But feel free to try MMO. And if that doesn't work, try some Haley's M-O. My brother puts that in his '63 Dodge Dart. It doesn't do anything for his lifters
either, but the car is incredibly regular.

Used cars can be a great bargain, and reliable, too! Find out why by ordering Tom and Ray?-s pamphlet How to Buy a Great Used Car: Things Detroit and Tokyo Don't
Want You to Know. Send $3 and a stamped (55 cents), self-addressed, No. 10 envelope to Used Car, PO Box 6420, Riverton, NJ 08077-6420.

?(C) 1999 by Tom and Ray Magliozzi and Doug Berman
Distributed by King Features Syndicate, Inc.

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