McDowell currently holds the 15th position in the series standings after achieving a seventh-place finish at the Chicago Street Race and a fourth-place finish at Atlanta.
He followed that up by posting the fastest average single lap speed (126.416 mph) to lead all competitors in Saturday’s practice.
“I typically struggle at New Hampshire, but that was a positive practice session,” McDowell commented. “Now we need to replicate that performance in qualifying.”
Martin Truex Jr. ended up second-fastest (126.408 mph) and Ross Chastain was third (126.077 mph). All three came from Group A.
Among those drivers who ran at least 10 consecutive laps, Truex had the best average speed (125.495 mph). He was followed by McDowell and Christopher Bell, respectively, in that category.
In the initial 20-minute sessions, McDowell completed the highest number of laps (26) and achieved the highest average lap speed (126.416 mph).
Truex was second-fastest (124.408 mph) and Chastain was third (126.077 mph).
Tyler Reddick and Bubba Wallace, who are teammates at 23XI Racing, finished in the top five positions.
Approximately 12 minutes into the session, Kyle Busch experienced a significant collision with the wall, resulting in damage to the right side of his No. 8 Chevrolet. Without delay, he proceeded to the pit road for necessary repairs.
Busch had stated over his team radio that the car was experiencing a significant loss of control before the collision.
Bell, who won this race a year ago, ended up fastest in the second 20-minute session (125.256 mph) but no one could match the speeds from Group A.
Daniel Suarez ended up second-fastest (125.248 mph) and Joey Logano was third (124.997 mph).
Kyle Larson was fourth and Ryan Preece, a former NASCAR Modified champion with a lot of experience at New Hampshire, rounded out the top five.