2015 WEC - A new ‘hot weather +’ soft-compound MICHELIN tire for the Circuit of the Americas cauldron
The 6 Hours of Circuit of the Americas (COTA) in Austin, Texas, USA, is the first non-European round of the 2015 FIA World Endurance Championship before the series moves on to Japan (October), China (early November) and, finally, Bahrain at the end of November.
The United States enjoys a long association with endurance racing and the country always extends a warm welcome to the FIA WEC due to its longstanding relationship with the Le Mans 24 Hours, while the championship’s world class entry list is a major draw for fans at the modern Circuit of the Americas.
Although inaugurated as recently as 2012, the Circuit of the Americas has rapidly established itself as a prime motor racing venue which hosts a number of top-flight events.
Its layout, which takes its inspiration from that of Silverstone, is only marginally shorter than its English counterpart (5.513km, compared with 5.89km) and it reproduces some of the latter’s characteristics, including its relatively twisty course. In total, it features 20 turns (nine right-handers, eleven left-handers) which is two more than Silverstone. It is consequently particularly hard on tires, especially since its surface – unlike Silverstone – is quite abrasive and the Texan weather at this time of year can be extremely hot, with track temperatures in excess of 40° C.
For the first time this season, Michelin’s partners will be able to use tires designed for the high temperatures expected in Austin, including a ‘soft hot weather +’ solution for the LM P1 prototypes.
“We have analysed how our tires performed at the last two 6 Hours of Circuit of the Americas races and that data has allowed us to develop tires which are suited to the track’s specific demands,” says Jérôme Mondain, manager of Michelin’s FIA WEC programme. “It is important to remember, though, that the asphalt is quite recent, so it still has a tendency to evolve in terms of the amount of grip it provides.”
The combination of slow turns, the very high torque levels delivered by the hybrid power units of the LM P1 cars and the frequent re-acceleration out of corners causes tires to heat up particularly quickly. As a consequence, Michelin has developed its ‘soft hot weather +’ tire to carefully contain temperature build-up, with no detriment to either performance or longevity. The latter is especially difficult to achieve since it is customarily antagonistic with the temperature parameter, wear being one of the simplest means to clear heat build-up.
Are different tire strategies possible?
At this season’s earlier six-hour races at Spa-Francorchamps (May) and the Nürburgring (August), Michelin’s solutions enabled the French firm’s partners to adopt varying tire strategies which had a decisive influence on the final outcome in Belgium and Germany. At Spa, Audi Sport took full advantage of the potential of its Michelin tires to begin double stinting before Porsche Team and thereby go on to win the race. At the Nürburgring, Porsche took revenge over its Ingolstadt-based rival to collect a one-two finish thanks to a strategy which capitalised on the durability of its tires.
“The Circuit of the Americas is a tough challenge. It is effectively hard to multi-stint but we are confident in the potential of our ‘soft hot weather +’ tire. This year, it will be important to take into account the fact that the LM P1 prototypes will only be able to use six sets of tires for the race, and that might prompt some teams to try different strategies based on how they use the different solutions at their disposal,” notes Jérôme Mondain.