- continued from Page 1 -

Tire Pressure
The amount of air pressure in a tire. During hard cornering a tire tries to shift sideways from the wheel, reducing its contact area and traction on the road. Increasing the pressure in a tire reduces the tendency to shift. (Never inflate a tire to a pressure greater than the maximum allowed by the manufacturer.)

Tire Section
The width of tire in relation to its height. A tire with a label of “195-60 14” has a width of 195 mm, a height of 117 mm (195 mm x 60%), and fits on a 14 inch rim. Increasing tire width increases the contact area of a tire, providing more traction. Reducing height decreases sidewall flex under load, also improving traction.

Wheel Width
The distance between the outside and inside wheel rims. Increasing wheel width reduces the tendency of a tire to shift sideways from the wheel, and maintains greater tire contact patch on the road.

Camber
The inward or outward tilt of the tire at the top, measured in degrees; the amount the tire is tilted from “true vertical.” Incorrect camber causes the front tires to wear unevenly. Positive camber is when the top of the tire tilts away from car; negative camber is when the top of the tire tilts towards the car. During cornering the outside wheels should be near vertical to maintain the greatest contact area and traction. As a car corners, body roll forces the outside wheel away from true vertical towards positive camber. This can reduce the contact area causing a loss of cornering traction. More negative camber will increase grip in turns, to a point.

Caster
The forward or rearward tilt of the steering spindle and the amount the center line of the spindle is tilted from the vertical, measured in degrees. Caster provides “trailing effect” for positive steering control, ease of steering, and ease of straight line tracking.

- continued on Page 3 -