Several drivers have told Motorsport.com, strictly off-the-record, about shifts in handling balance from one alternate tire set to another, as they lapped the 1.8-mile street and runway course in Pinellas County, FL.
The switch from primary [harder, black-sidewalled] tires to alternate Firestones [softer, red-sidewalled] will often see more than just an increase in grip all around, with some drivers adding front wing to counteract understeer because the rear tires get up to operating temperature quicker than the fronts.
However, a significant shift in balance from one set of tires to another of the same compound is far more unusual, and can leave a driver proverbially chasing his tail – and physically trying to catch the tail of an oversteering car.
One prominent driver who underperformed in today’s qualifying session for the second round of the 2021 NTT IndyCar Series season described the situation as “a lottery” regarding who did and didn’t get a “good” set.
Another spoke of a major balance shift catching out he and his team. Having struggled with understeer in practice – even FP2, when teams are able to try a set of the softer rubber – the driver said he suddenly suffered a “horrendous” run due to “zero rear grip”.
A third driver compared the situation to that at Barber Motorsports Park in 2019, when Firestone brought the red tires that had gone unused in 2018 due to that race being a wet event, necessitating the grooved tires. The theory then was that the rubber had cured and hardened in the intervening months.
However, Cara Adams, director of race tire engineering and production, told Motorsport.com that such was not the case this weekend at St. Petersburg.
“None of the tires are outdated,” she said. “The alternate tires – as well as the primary tires – were all made at the same time.
“There is no lottery for tire distribution. All drivers get the same tires to ensure consistency.”
Muddying the situation further, and perhaps altering driver perception is that the St. Petersburg track surface was not in its best state on Saturday afternoon, due to the Stadium Super Trucks corner cutting and dragging detritus onto the pavement during their first race, held just before IndyCar qualifying commenced.
Last year’s Grand Prix of St. Petersburg was held in October, as the series finale.