Myths about those little round things under your car.

Tire myths abound out in the automotive universe, ranging from price to durability to handling. But here are some of the more egregious myths, and when someone tries to sell you it, you can have an answer at the ready.

1.Tires should be inflated to the pressures indicated on the sidewall. No, inflate the tires to the pressures listed on the car information panel on the door or in the glove box or listed in the vehicle's owners manual. Cars are designed from the tires up.

2.A tread pattern is needed to provide great traction on dry roads. Not really, traction is a product of how much of the tire is in contact with the road, so ideally the best traction is with racing slicks (tires without tread) given a choice between two tires of the same size.

3.If not for cost, race tires would be ideal for high performance vehicles. No, they would be worse for high performance vehicles because tires used for Nascar are designed with individual tracks, likely weather conditions, and cars in mind. The tires used at the Daytona 500 for Jimmy Johnson's car are different than the tires used at Martinsville for the Goody's 500 for his car, those same tires that are used at Daytona in February are different from the tires that used at Daytona for the Coke Zero 400 in July. So you would end up with a ride that is rougher and doesn't handle as well using those tires.

4.Performance tires wear out because of the sticky compounds. The treadlife for performance tires is nearly identical to tires used on the family van. The real culprit is the aggressive driving: jackrabbit starts, quick stops, and hard cornering that most high performance vehicle owners perform, that will shorten the life of any tire.

5.Wide tires provide better traction. The other great traction myth, wider is better. No it isn't better, because as a tire gets wider, the weight becomes more dispersed, and the less weight bearing down on a section, friction is less so traction is decreased. In the case of snow tires, the tires are not going to dig through the snow and grab the road.

6.Tires are made of a single rubber compound. If the tires on a mountain bike on sale at Wal-Mart aren't made from a single compound, what do you think the odds are that tires are made out of a single compound?

7.A sidewall undulation indicates weakness. An undulation, as opposed to a bulge, occurs when materials overlap in the carcass of the tire. It may not look pleasing but those undulations are the strongest part of the tire. Most manufacturers are starting to use different construction techniques to remove those undulations and retain that same strength.

8.The best way to test a tire on the floor is to dig a fingernail into the tread and kick them. Well that is no and no, unless the goals are to get fingernails dirty and test shoe construction.