Formula One’s uncanny nature of off-track incidents dwarfing exponentially what was on it took a spectacular turn when Lewis Hamilton shattered the morale at Monza by winning with a margin of over 25 seconds before summoned to stewards for a post-race investigation of allegedly infringing the minimum starting tyre pressure requirements. It was all a smooth sailing for the Briton who led from pole position comfortably and extended his lead to Vettel by over 20 seconds until the closing stages of the 53 lap race.
The reigning world champion was asked by his race engineer Peter Bonnington to push harder to stretch his lead further without any explanation for the cause. There was an air of uncertainty prevailed in the Mercedes pits which blatantly revealed that the German team was expecting to alleviate time penalty by broadening the lead. The seemingly unending post-race deliberation continued for three hours as the left-rear tyre of Hamilton’s Mercedes W06 car was measured just before lights out on the grid to be 0.3psi below the minimum starting tyre pressure of 19.5psi strictly mandated by Pirelli for safety reasons in the wake of two tyre blowouts that marred the Spa weekend.
The Briton’s seventh victory of the season in his 160th race was upheld when stewards ruled that tyre pressures were at Pirelli’s recommended level “when they were fitted to the car” in the garage. Their detailed probe into what caused the temperatures in the tyres on both Hamilton and Rosberg’s car to drop when evaluated on the grid explained that the heated tyre blankets used to keep the tyres warm were unplugged at a lower than permitted temperature thus in turn the tyre pressures would have been dipped below the level recommended. The FIA stewards’ statement read,
“the tyre warming blankets had been disconnected from their power source, as is a normal procedure, and the tyres were significantly below the maximum permitted tyre blanket temperature at the time of the FIA's measurement on the grid.”
Before the race start, four cars in the first two rows: Hamilton, Raikkonen, Vettel and Rosberg had undergone tyre pressure checks. The results between them varied as the Ferraris were found to be above the minimum starting tyre pressure required while Hamilton was below 0.3psi and Rosberg on a deficit of 1.1psi. From the investigation’s outcome, it can be perceived that if the German driver had finished the race, he wouldn’t have been penalised as well.
With Pirelli’s conservative tyre pressure choices and to ward off such investigations again, an accurately outlined procedure should be emphasised for measuring tyre pressures as suggested by FIA stewards and also the man in charge for the German outfit. Mercedes’ Team Prinicipal Toto Wolff explained,
"You check the tyre pressures in the tyre heaters when you put them on the car,"
"This is the moment, because you could say 'when is the moment you should check them? Five minutes? Eight minutes from the end, when the red lights go on?'
"I think it is about defining the procedure – and the moment when those pressures are checked – in the future.
"We don't know why we had such a discrepancy. At the end of the day, it can cost performance if you have one tyre that has a different pressure than the others."