Technical Dictionary

Ultra-Low Profile Technology

Specialized sidewall shape, bead area, and bead compound that enhance the durability and mountability of tyres with very short sidewalls.

Under-inflation

Operating a tyre without sufficient air pressure to support the weight of the vehicle with occupants and additional load; could cause failure of the tyre when heat is generated inside the tyre to the point of degeneration of components.

Under-steer

The handling characteristic in which the front tires break loose because they are running a larger slip angle than the rear tires. Also known as plowing.

Undertread

Material between the bottom of the tread rubber and the top layer of steel belts; acts as a cushion that enhances comfort.

Unsprung Weight

The weight of the parts of a vehicle not supported by its springs, including wheels and tires, outboard brake assemblies, the rear axle assembly, suspension members, springs, shock absorbers and anti-roll bars.

UTQGS

Also known as Uniform Tyre Quality Grading Standards. A government-sponsored tyre information system that provides consumers with ratings (from AA to C) for a tyre’s traction and temperature. Treadwear is normally rated from 60 to 700.