Alexander Rossi had the quickest lap in the 30 minute warmup session for today’s Chevrolet Detroit Grand Prix. He also was fastest in yesterday morning’s practice session.

This morning’s practice was the cleanest of the weekend, stopped just once when Jimmie Johnson spun and stalled with about 15 minutes left.

The red alternate tires appear to degrade rather quickly. The teams have some big decisions to make on when to use them. Tire choices will be coming soon, and the starting tire could be the key to the race. There are many options, including a third stop.

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