The tires had previously only been used on an oval at North Wilkesboro during the ... race at Richmond Raceway After 31 laps and as the track surface dried out, NASCAR instituted a competition ...
Primary, or black, tires are the main compound used on every type of race track: Oval, road, and street. They’re the do-all tires that can handle the fastest superspeedway or the most fiddly ...