Carl Edwards led Thursday's only round of practice at the newly repaved and reconfigured Kentucky Speedway, site of Saturday night's Quaker State 400.
Edwards wheeled his No. 19 Joe Gibbs Racing Toyota to a best lap of 186.451 miles per hour, tops among the 40 cars in the field.
The leaderboard was top-heavy with Toyotas, as JGR drivers Kyle Busch and Denny Hamlin were second and fourth, respectively, with third place held down by Martin Truex Jr. of Furniture Row Racing.
The fastest non-Toyota belonged to Jimmie Johnson, who timed out fifth in his Hendrick Motorsports Chevrolet.
During the 85-minute session, there were a couple of incidents as both two-time Kentucky winner Brad Keselowski and Kasey Kahne had minor contact with the wall and Josh wise pulled in the garage with heavy smoke coming out of the front end of his car.
In five previous races at Kentucky, the only teams to win are JGR, which has three victories and two-time winner Team Penske. This is the only track on the Sprint Cup circuit where Chevrolet has never won.
Austin Dillon said the new track is still unique.
"The way the banking enters Turn 3 it's a flat corner and in (Turns) 1 and 2 is very high-banked," said Dillon, who ended the session in sixth place. "You run wide open getting through 1 and 2. In 3 and 4 you kind of have to back up your corner and figure out how to carry momentum and speed because of the banking. I think it's still Kentucky."
Check out the complete results from Thursday's Practice 1 below.