August 1989

---

Dear Tom and Ray:
I have a 1972 Mercedes 250. It uses regular leaded gasoline, which is getting harder to find at most service stations. When I have to use unleaded gasoline, should I add one of the lead additives that are available in auto parts stores, or should I use a higher octane unleaded gasoline?
Terry

RAY: Your's is what we call a lost cause. The leaded gas sold today has just a trace of lead...as do the lead additives you mention. The additives, as you've probably noticed, are also very expensive. The purpose of the lead was to protect the valve seats, which get pounded as the engine runs. Rather than fight this, your best bet is to just drive it. If the valve seats ever get destroyed, spend a few hundred bucks and replace them. But you may never have to do it--especially on a car as tough as a Mercedes.

TOM: I noticed that your letter is postmarked from New York City. Another option would be to put some water in your tank. There's probably enough lead in those New York City water pipes to keep this car humming for years.

Back to the August 1989 index

Share this column with a friend.

© 2006 by Tom and Ray Magliozzi and Doug Berman. Distributed by King Features Syndicate, Inc.

---

---

Auto repairs can be costly! Save money by ordering Tom and Ray's pamphlet: "Ten Ways You May Be Ruining Your Car Without Even Knowing It!" To order, send (check or money order) to Ruin, P.O. Box 536475, Orlando, FL 32853-6475. You can also order online.