Kyle Larson switched to a backup car after being involved in a crash during Daytona 500 practice Wednesday.

Larson was involved in a multi-car accident in the second practice session, a pileup that occurred after Ty Dillion cracked an oil cooler between Turns 1 and 2 at Daytona International Speedway.

Dillon spewed oil on the track and on other drivers' windshields, and as cars behind him tried to slow, two-time Daytona 500 champion Michael Waltrip ran into the back of Ryan Newman. Both cars spun, and Waltrip hit the outside wall. He was transported to the infield care center, evaluated and released.

Larson and Chris Buescher also were caught up in the mess, and the damage to Larson's car was bad enough that his team opted to move to the backup.

Michael McDowell, who needs to race his way into the Daytona 500 in one of the two qualifying races Thursday, posted the fastest lap in the early practice. McDowell reached 200.173 mph, a tick faster than Trevor Bayne, Greg Biffle and Ricky Stenhouse. Jr.

Brian Scott topped the second practice, reaching 199.800 mph. Austin Dillon was second, followed by Kyle Busch, Jimmie Johnson and Paul Menard.