McDowell, who was part of a group of Fords that elected to draft with just minutes remaining in the 50-minute session, turned in an average lap speed of 192. 735 mph.
David Ragan, driving a Rick Ware Racing car, ended up second (192.665 mph) and Todd Gilliland – McDowell’s teammate at Front Row Motorsports – was third (192.649 mph). Brad Keselowski and Chris Buescher rounded out the top-five.
The remaining drivers in the top-10 were Martin Truex Jr., Bubba Wallace, Denny Hamlin, Kurt Busch and Kyle Busch.
Kyle Busch said his No. 18 Toyota car handled much different on the track than last year’s Gen-6 version.
“They’re different in the air. They’re different with the way they’re in line and push and how much suck up you get from the cars in front of you versus having no one behind you or someone behind you,” he said.
“There wasn’t much to learn. It’s going to take 20 to 25 of us to get a really good sense of what really happens and we won’t see that until we get to the Duels (qualifying races).”
Toyota was the first manufacturer to send a group of its cars out to draft during the practice. All 44 entries in the race took at least one lap of practice with Greg Biffle and his NY Racing Team the last to hit the track.