Back in the early days of Lewis Hamilton’s Mercedes tenure, a scandal enveloped the team over a ‘secret test’ it had conducted with Pirelli.
F1 rules at the time dictated that bar the official young driver test, testing was expressively banned in-season.
But Nico Rosberg’s victory in the 2013 Monaco Grand Prix was overshadowed by the news of Mercedes conducting a three-day, 1000km test with its 2013 car, with the German and Hamilton as drivers, on behalf of Pirelli after the Spanish GP.
Mercedes and Pirelli tyre test
The 2013 Mercedes, the W04, had a problem: it had a ferocious appetite for Pirelli tyres.
The rear tyres, in particular, degraded alarmingly quickly, to such an extent that during the Spanish GP, Hamilton, who had qualified in second place, was lapped, finishing 12th for his worst result until the 2021 Azerbaijan GP nearly eight years later.
Pole-sitter Rosberg finished sixth, more than a minute down on winner Fernando Alonso as Mercedes tried desperately to understand why its car was so tyre-hungry.
Tyre supplier Pirelli had a contract with the FIA to allow it to do some limited running and approached Mercedes to do so to test new tyres set for introduction later in the 2013 season.
Both Pirelli and Mercedes then approached the FIA’s Charlie Whiting for approval for the test with the W04. Although Whiting was not in a position to formally green-light the running, his word was considered impeccable. It is believed he signalled that it could take place if the other teams were afforded the same opportunity.
Pirelli had already asked the other teams in general terms if they would run when asked, and both Pirelli and Mercedes deemed it to be sufficient to run the test in the days after the Spanish GP.
Both Hamilton and Rosberg wore blacked-out helmets instead of their traditional designs, as rival teams Red Bull and Ferrari caught wind of the test on Saturday evening in Monaco.