Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, July 19, 1990                   TAG: 9007180254
SECTION: EXTRA                    PAGE: E-4   EDITION: METRO 
SOURCE: Tammy Poole
DATELINE:                                 LENGTH: Medium

MIXING TIRE TYPES NOT RECOMMENDED

A: No. According to the Virginia State Police inspection manual, it is acceptable to have radial tires on the back wheels and bias ply tires on the front wheels of your car. However, the reverse is not acceptable: radial tires on the front, and bias ply on the rear. It is also not safe to have mismatched tires on the same axle, according to the manual.

According to Jim Schepmoes of the National Tire Dealers and Retreaders Association in Washington, the inspection rules are in place because of safety considerations. Having radials on the rear and bias tires on the front give you better control of the vehicle. "If you switch them around, you won't have good control, which could lead to an accident," Schepmoes said.

Tire buyers have three principal types of tire construction to choose from:

Radial - In these tires, cords run directly across the tire from bead to bead (the point where the tire touches the rim). Radial tires have belt plies under the tread to reinforce the tire. This tire is the only type of tire available as originial equipment on passenger cars sold in the United States. Radials comprise over 90 percent of the replacement market, according to the Better Business Bureau.

Diagonal (bias): These tires may have two or more body plies which cross at an angle of approximately 35 degrees to the centerline of the tread.

Belted bias: These tires have a body similar to that of bias tires, plus two or more belts under the tread.

For the best and safest ride, "it's preferred that all four tires be of the same size and construction, either all radials or bias . . . When radials first came out, they were expensive. Now there's not that much difference in price," Schepmoes said.

All tires wear out eventually, but you can prolong tire life if you observe these precautions provided by the BBB:

Maintain proper tire inflation pressure.

Rotate tires every 6,000 to 8,000 miles, or sooner if irregular wear occurs.

Check tire balance, wheel alignment and suspension when tires are rotated, or if uneven or rapid wear occurs.

Don't overload your car.

Avoid "jack-rabbit" starts and panic stops, driving at excessive speed, and fast turns on curves and around corners.

Avoid driving over curbs, pot holes and rough roads at excessive speeds.