The NTT IndyCar Series completed its first practice session of the weekend on Friday afternoon, with drivers tackling the always-enjoyable Road America.
The 4.01-mile course provides ample amounts of elevation changes and long straights to let the 800-plus horsepower cars stretch their legs.
At the top of the timesheets following the session was Marcus Armstrong in the #66 Meyer Shank Racing Honda.
The New Zealand native used the softer compound tires to put in a lap of 1:44.2417 at an average speed of 138.585 MPH.
His Swedish team-mate Felix Rosenqvist was not far behind, and set the second best time of the day.
Alex Palou was at the top of the timesheets for a good portion of the afternoon, but slipped down to third when the softer red tires were fitted.
The Spaniard still showed plenty of speed, however, but it seems the primary tires are where his car works best.
Pato O’Ward and Nolan Siegel were fourth and fifth fastest respectively, giving both Arrow McLaren and Chevrolet representation in the top five.
Rookies fared well on Friday, with Caio Collet setting the sixth best time and Mick Schumacher ending the day in eighth.
The only stoppage of the session was for Sting Ray Robb, who went wide at the exit of Turn 14 and spun onto the main straight.
His Juncos Hollinger Racing Chevy bounced off the tire barriers with both the front and rear ends, which resulted in a tow back to pit lane.
Scott McLaughlin nearly crashed in the same spot earlier in the session, but was able to keep control of his car in the moment.
There were a few other locked up tires as drivers found the limits of their cars, but no other incidents stopped the action.
Drivers will be back on track Saturday at 10:00 AM central time for the second practice of the weekend.