What was the Mercedes secret tire test controversy? When Lewis Hamilton and Nico Rosberg were part of a secret test conducted by the team

Right before the start of their dominant era, Mercedes was involved in a secret Pirelli tire test controversy back in 2013.

Tires are one of the most important parts of an F1 car. They play a massive role in terms of grip, balance, longevity of a stint, and more. Hence, when it was discovered that the Silver Arrows were involved in a secret tire test with Pirelli and their drivers, Lewis Hamilton and Nico Rosberg, the FIA's International Tribunal began a serious investigation.

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All about Mercedes' secret Pirelli tire test

For quite some time, the FIA F1 Sporting Regulation had a rule that clearly stated that teams are not allowed to test current F1 cars during the season, apart from straight-line aerodynamic tests and Young Driver tests. Any other kind of test had to be done on cars that were a few years old.

In 2013, Pirelli faced a lot of criticism from teams regarding the amount of tire wear. This induced the Italian tiremakers to conduct a tire test and introduce new tires to the Canadian GP. Ferrari and Mercedes took part in the tire tests, but neither team was aware of the other's tests.

The Prancing Horse did a 500-kilometer test with their 2011 car before the Spanish GP, while the Silver Arrows conducted a test with Pirelli for three days after the Spanish GP at Barcelona.

There were essentially two issues with Mercedes' tire test: it was done in complete secrecy, and the team used their current 2013 F1 car and drivers for the test.

Pirelli came out and clarified that the tire test was not discussed openly because it would have prompted heated discussions and politics, eventually canceling the test. Hence, they only contacted the FIA and interested teams to quietly conduct the test.

The main issue arose when the FIA said it was not aware that Mercedes was running their 2013 car with their current driver lineup.

On the eve of the 2013 F1 Monaco GP, complaints from Ferrari and Red Bull flew over to the FIA that the Silver Arrows could have gotten a massive competitive advantage by using their 2013 F1 car for Pirelli tire testing.

During the Canadian GP, the FIA announced that they were referring the secret tire test to its International Tribunal. Eventually, the tribunal reprimanded Mercedes and Pirelli for breaking the rules for the tire test. The team was ordered to skip the three-day young driver test scheduled in Silverstone in July.