Allmendinger, who has four NASCAR road course wins to his credit (three in Xfinity and one in Cup), paced the first practice session with an average lap speed of 97.392 mph.
He was the only drive to eclipse the 97 mph on the 2.439-mile, 14-turn course, which is also used by the IndyCar Series.
Austin Cindric ended up second (96.803 mph) and series points leader Chase Briscoe was third (96.470 mph). Justin Haley (96.213 mph) and Justin Allgaier (95.976 mph) completed the top-five.
Rounding out the top-10 speeds were Jeremy Clements, Noah Gragson, Josh Bilicki, Ross Chastain and Preston Pardus.
There weren’t any serious incidents during the session.
Ryan Sieg spun once off Turn 12 and Josh Williams drove off course once but was able to continue on without damage.