Drawing firm conclusions from the Roar Before the Rolex 24 at Daytona always is a dicey proposition. With IMSA officials keeping a watchful eye on manufacturer disparities, teams also are mindful about showing their hand.

Daytona's annual sports-car run, the Rolex 24, began in 1962 as a 3-hour effort. It's been won by Mario Andretti and Paul Newman, among other stars.

With 61 sports cars ready to get on track today, key storylines for the 63rd running of the 24-hour classic at Daytona International Speedway.

The final day of IMSA testing during the Roar Before the Rolex 24 at Daytona International Speedway will be impacted by rain.