The series says teams will be required to use at least two sets of both alternate and primary tires, making next week's race ...

IndyCar teams will be required to use two sets of both primary and alternate tire compounds during next weekend's Sonsio Grand Prix on the Indianapolis Motor Speedway road course, altering a long-used ...

Tread depth is an important tool to measure whether a tire is safe to drive on, but that doesn't explain the unusual ...