What’s idea with tiny-sidewall tires?

Dear Bob: Tires have improved greatly through the years. So what is the story with these new tires with tiny sidewalls?

Are they simply for looks, or do they reduce disposal pollution, increase passenger comfort, help handling, increase gas mileage or travel more miles before they wear out?

— Sincerely, E.S., via e-mail

A: Low-profile tires — those with sidewalls a mere inch or two high — are meant to be performance-oriented, although they have found other venues in which to strut their stuff.

Because there is little sidewall to flex on hard turns, the low-profile tires provide crisper, more easily controlled handling than you get with comparable standard-sidewall tires. That’s why these tires are found almost exclusively on smaller sports cars and performance-oriented vehicles for which handling is at a premium.

Of course they have also impressed with their looks, and I’ve seen many a low-rider equipped with these tiny-sidewall tires, presumably because of the cool, extra-low look they provide.

Forget passenger comfort, because low-profile tires are strictly for handling and performance and pay little heed to the ease of the vehicle’s occupants. With no wide sidewall to flex and absorb irregularities in the road, every pebble and every bump lets you know unmistakably that it’s there.

The same is true of the steering: With these tires you’ll feel every signal the road has to offer, coming directly through the steering column to the steering wheel and into your hands.

It’s interesting that you mention “reducing disposal pollution,” though, because in this area there is an advantage. The low-profile tires are much smaller, of course, and therefore won’t add to the used-tire burden as much as larger-sidewall tires do. And they should provide a bit better fuel economy as well, mainly because they produce less rolling resistance.

As far as longevity is concerned, their anticipated life is stamped on the sidewall — if enough room can be found! — with a treadwear number. Comparing this number to the number on a comparably sized standard sidewall will tell you if the low-profile will last longer or not.

Dear Bob: I have a 2002 LeSabre and have had trouble with the “gas cap loose — check cap” warning message.

It will come on any time I am driving. I had it checked at the dealer, and they couldn’t find anything wrong. They did put a new gas cap on, though, and it seemed to work fine for about three weeks.

Now, when I start the car and before the DIC (driver information center) displays the miles, the light comes on again. After I reset it, it does not go on again until the next time I start the car.

— L.H., via e-mail

A: Trouble codes recorded in the vehicle’s computer should be enough to give the shop an idea of what part of the system is causing the warning light to come on.

Since the gas cap is part of the emissions-control system, I suspect that your problem might lie elsewhere in that system. My guess is that there is some problem in the gas tank’s vent line, which is routed from the tank to the charcoal canister in the engine compartment.

AMERICAN DRIVERS FIGHT BACK

Here’s a tip that will help you get better gas mileage while fighting terrorism and cutting our nation’s dependence on Mideastern oil:

Dear Bob: I have a great idea that American drivers can use to save untold gallons of gas per year: Stop going through drive-throughs.

Imagine how much gas we use waiting in line at drive-throughs, be they fast-food restaurants or bank lines. Park your car and go inside! What really gets me is the people who use the drive-through and then drive over to a parking spot and park. We need to walk the 30 feet to the door in order to conduct business inside.

I have talked to my state representative about imposing a drive-through tariff that people would pay to use the convenience of a drive-through. The money would go to the state, but he does not want any part of a tax increase.

In the meantime, people, you can save gas and burn off the extra calories by walking back and forth to your car.

Thanks, Bob.

— B.B., Woodstock, Ill.

A: This was one of the suggestions I made in my book, “How to Get More Miles Per Gallon,” way back in 1976. Since then drive-throughs have proliferated, offering us more opportunities than ever to save gas and burn calories.

However, one look at the average Joe or Jill is enough to tell me that very few have taken advantage of those opportunities.