Q&A: Oil change

February 28, 2001
Web posted at: 13 4 GMT

By Jim Mateja

CHICAGO (KRT) - Is 3,000-mile oil change necessary or just a myth? What do you do when the auto manufacturer and tire company have different recommendations on your maximum tire pressure? Why do some people tap on the hood before starting their cars?

Jim Mateja, who answers questions below, is an auto columnist for The Chicago Tribune.

Q: I read one of your columns in my local paper about 3,000-mile oil changes being the best call. I've always changed oil and filter at 3,000 miles but was about to change that practice after reading in a magazine that the 3,000-mile oil change is a myth and a brilliant gimmick fostered by quick oil change outfits to get business. The article said every owner's manual specifies oil type and change intervals, and no damage or excessive wear will occur if you follow those schedules, which often don't call for a change for 6,000 to 10,000 miles if not longer.

- C.K., Durham, N.C.

A: The 3,000-mile or three-month, whichever comes first, oil-change recommendation was a rule of thumb long before quick oil change outfits entered the picture. Follow the recommendation in the owner's manual, but remember that when the manual says you don't have to change oil for 5,000 or 6,000 or even 10,000 miles, it typically adds "under normal driving conditions." But if you experience "severe driving conditions," you must change oil more frequently. Normal means you drive many continuous miles nonstop at optimum temperatures as opposed to severe, or stop-and-go short hauls or letting the car sit days or weeks at a time before driving it, when condensation becomes a villain as well.

But the choice is yours; spend $20,000 on a new car and save $20 by prolonging the oil change to 10,000 miles or spending the $20 and prolonging the life of your $20,000 car by 10,000 or more miles.

By the way, when your engine starts to act up and you pull into a shop for service, what is the first question the mechanic will ask? It's not "Do you want a cup of coffee?" or "How do you always look so good?" It's "And when was the last time you changed your oil?"

Could you be changing oil too much and wasting $20? Perhaps. But what are the consequences of changing oil too little to save $20?

Q: I have a Chrysler 300M. Great car. Goodyear recommends I inflate the tires to 44 pounds, but Chrysler recommends I inflate the tires to only 30 pounds. What should I do?

- M.R., Lincolnwood, Ill.

A: We called Dave Wilkins, spokesman for Goodyear Tire & Rubber Co., in Akron, Ohio, and he said to inflate your tires to 30 pounds as recommended by Chrysler.

"Always inflate your tires to what the auto manufacturer recommends, not to the maximum pressure printed on the tire sidewall, which in this case is 44 psi," Wilkins said.

Sounds like when you say "Goodyear" and "Chrysler," you were referring to a Goodyear and a Chrysler dealer, not the factory.

Q: As for rotating tires, my owner's manual says to rotate the tires on my front-wheel-drive Buick by moving the right front to the right rear, the left front to the left rear, but the right rear to the left front and the left rear to the right front. But then I went to a muffler shop and the man said to rotate right front to right rear and right rear to right front and left front to left rear and left rear to left front. He said the tiremakers recommend this rotation.

- R.H., Mount Prospect, Ill.

A: Once our head stopped spinning from trying to get a handle on your rotation choices, we got back on the phone to Wilkins, who represents one of those tiremakers, and he said when it comes to rotation on your front-wheel-drive Buick:

Left front to left rear, right front to right rear, but then crossover and rotate left rear to right front and right rear to left front.

"We also suggest a tire rotation every 6,000 to 8,000 miles or at any sign of uneven wear. And keep in mind that the first rotation is the most important one," Wilkins said. That will establish your wear pattern and increase or, if not done at the right time and in the correct pattern, decrease the expected life of the tires.

Q: Fogged-up windows are driving me bananas. What to do?

- P.T., Naperville, Ill.

A: Look on your dash for those symbols showing an arrow coming into the car from outside and an arrow inside the car. Put the control lever on the symbol of the arrow coming into the car from the outside. And don't push the heat control lever all the way to boil, because blasting cold windows with hot air isn't going to solve the problem. At initial startup, you also might want to hit the button for air-conditioning, which is designed to get moisture out of the car and thus off the windows.

At one time a blackboard eraser was recommended to use when moisture started to build on the windshield, but in this age of computers, finding a blackboard, much less an eraser, is no easy task.

Q: Advice on preventing my carpets from looking like they've been placed at the door to the main terminal at O'Hare?

- J.G., Chicago, Ill.

A: You mean your car carpets, we hope. Consider getting a carpet remnant to place over the factory-installed carpeting in your vehicle in the winter, a small piece for driver and passenger side that get the most abuse and a small piece in back for passengers. And make it a small remnant so it doesn't get stuck under the pedals. When it gets soiled or wet you brush it off or shake it out and put it back down again or, if very wet and dirty, toss it out and use another remnant.

Q: I just caught a few minutes of a show on cable TV in which a man advised that in the wintertime, if you park your car outside you should tap on the hood before starting the car so that any cats that sought shelter from the cold underneath would have a chance to flee. Good advice.

- M.D., Waukegan, Ill.

A: Excellent advice. Of course, if it is bitterly cold, you could always send your Great Dane out to the car to perform the task.

-- Jim Mateja is a nationally-syndicated columnist who writes about the auto industry for the Chicago Tribune.