February 19, 2004

By BOB SIKORSKY / Distributed by The New York Times Syndicate

Dear Bob: I have a late-model Cadillac Escalade that seems to be using more oil than it should. I changed the brand of oil I was using and switched to a higher viscosity, all to no avail. The vehicle still seems to be burning a quart of oil every 1,500 miles. While many people may think this is OK, I am not happy about it.

My service manager doesn't know what else to do. Can you help?

Sincerely, D.B., Cocoa Beach, Fla.

A: While you don't say what year your Escalade is or note the type of engine, there is a good chance your car is among the GM vehicles that have been plagued by excessive oil consumption. A number of 1999-2002 Chevrolet and GMC full-sized pickups and SUVs, along with some Cadillac Escalades with V-8 engines, have had this problem.

General Motors does have a fix for this and I'm surprised your service manager didn't mention it to you. The oil use in many cases can be traced to a positive crankcase ventilation, or PCV, valve whose flow rate is restricted under certain driving conditions. The remedy is to change the type of PCV valve being used from one with a spring and plunger -- most probably what you have -- to one with a fixed orifice that has no moving parts. In most cases this will solve the problem. Your GM dealer should have the part.

In the unlikely event this doesn't help, you'll have to look elsewhere for the cause.

Dear Bob: I hope you can help me out. I have been looking around for information about a part to install in my vehicle's air cleaner that's supposed to improve power and give me better fuel performance. It's called a Tornado fuel saver. I think it costs around $80.

I have a 2002 Ford F-150 and get very poor gas mileage. Do you know anything about this product?

W.P., Belleville, Ill.

A: I know a lot about this product -- including the fact that it doesn't work and that the manufacturer has no industry standard tests to back up his ridiculous claims. Incidentally, I have a number of these devices on a shelf in my garage. They were sent to me so that I could test them. I did, and found absolutely no improvement in either power or fuel economy on a number of vehicles tested. These things were a rip-off when they were selling for around $30, so at $80 they are really going for the jugular.

My advice: Save your money and don't even think about buying one of these worthless items. Use that $80 for fuel for the F-150. You'll go a lot farther on 80 bucks worth of gas than on $80 worth of wishful thinking. And next time, don't purchase a vehicle that gives you poor fuel economy when fuel economy is one of your concerns.

Dear Bob: I read your column and have most of your books. They are great.

My question: After I ran over a cardboard box, my speedometer stopped working. The "D," indicating that I was in "Drive," began flashing and then stopped. I went to a dealer who could find nothing wrong.

Everything is working fine now, but what do you think happened?

Thank you. P.K., Tolland, Conn.

A: The cardboard box had to have made contact with an electrical connection under the vehicle that caused the temporary symptoms you describe. If the symptoms reappear, have the wiring underneath the car, especially the one leading to the transmission, checked for a loose connection.

American Drivers Fight Back

Here's a tip that will help you get better gas mileage and cut our nation's dependence on Mideastern oil:

It's much easier and more economical to perform difficult maneuvers such as parking when the engine is warm rather than cold. Components such as the power steering pump and gears, wheel bearings, transmission and differential or transaxle work more efficiently when their respective parts are warm.

Overnight, always park your car so that leaving in the morning will be easy. Do all backing up, turning and other maneuvering while the engine is warm and at its most efficient. You'll be surprised at how much gasoline you can save with this simple technique because you dramatically ease the power and fuel requirements of a cold and very inefficient engine.

(Bob Sikorsky, a national-award-winning journalist who has written several best-selling books on automotive care, is a consultant in that field and a member of the Society of Automotive Engineers and of the Society of Tribologists and Lubrication Engineers. Questions or comments of general interest should be e-mailed with the subject line: "Attention Bob Sikorsky", to: autos@belointeractive.com. Bob Sikorsky regrets that he cannot answer questions individually.)

Copyright 2004 NYT Syndication Sales Corp.