A traemark of Goodyear, it was the name of a bias belted tire introduced in 1967 which generally had a wider tread than most other tires on the market at the time and used belts made of fiberglass. It was initially was an original equipment tire on late 1960s muscle cars such as the Pontiac GTO, Dodge Charger R/T, Ford Mustang Mach I, Chevrolet Camaro Z-28 and many others along with comparable tires from various competitors such as the Firestone Wide-Ovals. The Goodyear Polyglas and comparable bias-belted tires began appearing as standard or optional equipment on many 1969-model passenger cars and nearly all 1970 to 1974 models. The most common version of the Polyglas found on muscle cars of that era was the Polyglas GT, which was one of the first commercially available raised white lettered tires on the market. Other versions of the Polyglas lineup were offered as blackwall or whitewall tires.