Denny Hamlin posted the top speed in the final Cup Series practice session Saturday at Texas Motor Speedway.
Hamlin recorded a speed of 186.987 mph.
Johnson, who will start from the pole, had the best 10-lap average at 184.366 mph.
Most of the top speeds came late in the session when a large group of cars ran together in essentially race conditions.
“Just trying to get around each other and figure out what your car is in balance and traffic,” Hamlin told Fox Sports 1. “You certainly don’t want to have anyone in front of you, that’s for sure. It’s extremely tough to get around someone, unless they bobble and get out-of-the-way. There’ll be plenty of passes in and around the field because people are going to get out of shape following someone else. But once you’re out front, man, you can just take off and go.”