Firestone Firehawk Race Tire Facts for the Sonsio Grand Prix at Road America

The NTT INDYCAR SERIES heads to Elkhart Lake, Wisconsin, this weekend for the Sonsio Grand Prix at Road America, the fastest road course on the circuit. The legendary track will also play host to the INDY NXT by Firestone Grand Prix at Road America. 


Firestone is supplying more than 1,600 race tires to teams and drivers as they take to the 4.014-mile, 14-turn natural terrain road course for practice, qualifying (including the Firestone Fast Six), and Sunday’s 55-lap (220.55 miles) race.  

The primary and alternate tire construction for this weekend’s event is the same as was supplied for the 2022 Road America event. The primary compound is the same as that which was used for 2019 Road America race, while the alternate compound is the same as the 2018 Indianapolis road course primary compound. This weekend’s rain tires are the same constructions and compounds as those released in 2018. 

Each NTT INDYCAR SERIES entry will receive the following allocation: 

  • Primary (black): 7 sets per entry* 
  • Alternate (red): 4 sets per entry 
  • Rain (gray): 5 sets per entry 

    *Rookies will receive one extra set 

Each entry must use one set of primary and one new set of alternate tires in the race. One additional set is available to teams fielding a rookie driver. 

Cara Krstolic Notes:
Road America is historically INDYCAR’s fastest road race accompanied by an elevation gain of about 211 feet per lap which totals a climb of 11,600 feet in the 55-lap race. To help tackle the elevation gain on the 4-mile-long natural terrain road course, Firestone modified its standard road course tires with slightly less tread gauge and lower thickness to assist with load changes and generate more temperature through turns. With the newly paved surface, both primary and alternate tires will be more heat resistant with improved wear. 

INDY NXT by Firestone 

Firestone is supplying nearly 500 race tires to INDY NXT by Firestone teams and drivers for practice, qualifying, and the 20-lap (80.28 miles or 55-minute) race on Sunday. 

Each INDY NXT by Firestone entry will receive the following Firestone Firehawk race tire allocation: 

  • Primary: 4 sets per entry 
  • Rain: 2 sets per entry 

Cara Krstolic Notes on INDY NXT tires

The INDY NXT tire for Road America is similar to the other road and street course tires but with a lighter gauge and a more durable compound to adapt to the high speeds of the natural terrain road course.