Road America: #55: Alex Palou, Dale Coyne Racing with Team Goh Honda, #28: Ryan Hunter-Reay, Andretti Autosport Honda, #12: Will Power, Team Penske Chevrolet, #9: Scott Dixon, Chip Ganassi Racing Honda, #18: Santino Ferrucci, Dale Coyne Racing with Vasser Sullivan Honda, #1: Josef Newgarden, Team Penske Chevrolet
#55: Alex Palou, Dale Coyne Racing with Team Goh Honda, #28: Ryan Hunter-Reay, Andretti Autosport Honda, #12: Will Power, Team Penske Chevrolet, #9: Scott Dixon, Chip Ganassi Racing Honda, #18: Santino Ferrucci, Dale Coyne Racing with Vasser Sullivan Honda, #1: Josef Newgarden, Team Penske Chevrolet