More and more motorists seem to be driving around in cars sitting atop what look like rubber bands: low profile tires on giant alloy wheels.
Those "rubber bands" are actually high performance or touring tires, and they're wildly popular among consumers who like a muscular, sporty look.
For The Record
Los Angeles Times Wednesday August 30, 2006 Home Edition Highway 1 Part G Page 2 Features Desk 2 inches; 77 words Type of Material: Correction
Tire size: A column on high-performance tires in last week's Highway 1 section gave an incomplete equation for figuring the aspect ratio of a tire, a figure generally used to describe the size of a tire's sidewall. The story suggested taking the diameter of a tire, subtracting the diameter of the rim and then dividing by the width. It failed to include the last two steps: converting diameter size from inches to centimeters and dividing by two.
But like an injury-prone star athlete, the buff body disguises some weaknesses. If you don't think so, just ask Los Angeles County Superior Court Judge Lance Ito.
Ito wrote to me recently about his two Audi A6s, whose low aspect ratio tires have had nine flats in the last 40,000 miles. He has gone through three sets of tires in that time. "I will never again buy a car with these low-profile tires," Ito said. You can almost hear his gavel bang.
In fact, engineers and safety experts say low aspect ratio tires -- which have shorter sidewalls -- are more vulnerable to road hazards, such as potholes and other obstructions that can test a tire's ability to flex at high speed, than their standard counterparts.
Officials from Goodyear, Michelin and Bridgestone -- the three largest tire makers -- all acknowledged in interviews that their low aspect ratio tires are more likely to be damaged by impacts in normal driving.
"They are more susceptible to pothole damage," said Bill VandeWater, Bridgestone's consumer tire products manager, in Nashville. "They don't have as much give before the tread contacts the rim. There isn't as much deflection capability as a taller tire."
What can you do about it? Well, advice from manufacturers can be kind of silly. Take, for example, Volkswagen's suggestion. "Avoid driving on roads with potholes, deep gouges or ridges," it tells owners of cars equipped with these tires. In other words, keep the car in the garage.
Nonetheless, consumers like the look. At Michelin, 20% of the tires it sells are high performance, and that figure is growing by about 10% annually, while sales of the standard "mass market tires" for cars are shrinking, said Lynn Mann, director of public relations for the tire maker.
Although consumers like the low-profile tires, safety experts are dubious about their practicality.
"My observation, other than styling, is why have them?" asks Clarence Ditlow, executive director of the Center for Auto Safety in Washington, D.C. "My advice to consumers is don't buy them."
Perhaps. But many don't have a choice. Manufacturers are offering autos with wheel wells designed to fit only a low aspect ratio tire, especially luxury cars with a sporty image.
