Ford Explorer, Maintaince And Repair Manual

Page: 112 / 1119

P−Metric tire coding
Click to enlarge
CAUTION
Radial tires should never be used on only the front axle.
When selecting tires, pay attention to the original size as marked on the tire. Most tires are described using an
industry size code sometimes referred to as P−Metric. This allows the exact identification of the tire
specifications, regardless of the manufacturer. If selecting a different tire size or brand, remember to check the
installed tire for any sign of interference with the body or suspension while the vehicle is stopping, turning
sharply or heavily loaded.
Snow Tires
Good radial tires can produce a big advantage in slippery weather, but in snow, a street radial tire does not
have sufficient tread to provide traction and control. The small grooves of a street tire quickly pack with snow
and the tire behaves like a billiard ball on a marble floor. The more open, chunky tread of a snow tire will
self−clean as the tire turns, providing much better grip on snowy surfaces.
To satisfy municipalities requiring snow tires during weather emergencies, most snow tires carry either an M
+ S designation after the tire size stamped on the sidewall, or the designation "all−season.'' In general, no
change in tire size is necessary when buying snow tires.
Most manufacturers strongly recommend the use of 4 snow tires on their vehicles for reasons of stability. If
snow tires are fitted only to the drive wheels, the opposite end of the vehicle may become very unstable when
braking or turning on slippery surfaces. This instability can lead to unpleasant endings if the driver can't
HOW TO USE THIS BOOK
98 TIRE DESIGN