Silverstone: Michelin preview

TYRE CHOICES COULD DECIDE LE MANS SERIES TITLES

Michelin is putting the final touches to its preparations for Sunday's 1,000km clash at Silverstone which will host the fifth and final round of the 2008 Le Mans Series this weekend.

This race will settle the fight for both the Drivers' and Manufacturers' titles between Audi Sport and Peugeot Sport which has won all the races contested so far this year. The decision has gone done to the wire, too, between Van Merksteijn Motorsport and Team Essex in the LMP2 category, while Team Luc Alphand Aventures enjoys a 36-point cushion in GT1 and has every chance of warding off the challenge of Team Modena to secure the 2008 crown.

For the season's final showdown, Michelin will once again seek to deliver the best possible products and service to its partners in order to help them achieve their respective objectives. The French firm is equally highly aware that Silverstone is one of the calendar's most exacting circuits; rain could well upset the established pecking order and, in that case, a poor tyre choice could produce some dramatic changes at the top of the standings in all three categories.

This weekend promises to particularly busy for Michelin which will also have staff in the Czech Republic for the seventh round of the FIA GT Championship at Brno where the tyre firm will be working with 23 cars. Taking both events into account (LMS at Silverstone, and FIA GT at Brno), Michelin will have more cars running on its tyres on Sunday than it did during the Le Mans 24 Hours in June!

The circuit
Length: (length: 5.141km)

Mathieu Bonardel (Four-wheel Programme Competition Director, Michelin):

"The layout of Silverstone means it's got a bit of everything. Unlike other venues which tend to be earmarked as either slow or fast, Silverstone features a complete spectrum of very different corners which range from slow to medium-fast and very fast. The track gives good grip in dry conditions, although the surface is quite abrasive. As the weekend progresses, more and more rubber is laid down and this changes the balance of the cars which frequently suffer from under-steer on the Friday whereas the tendency on the Sunday is over- steer since the front tyres enjoy better grip and the rears tend to wear. In wet weather, this track doesn't drain very well and becomes very slippery."

The tyres

Matthieu Bonardel (Four-wheel Programme Competition Director, Michelin):

"This circuit is very tough on tyres because there are numerous places where the drivers accelerate hard as they sprint from one turn to the next. Silverstone tends to be a high speed circuit, so there is quite a big load on the tyres and there are few straights to speak of to give them a chance to breathe.

"In LMP, the medium compound is a very competitive option and superior to the softs in terms of endurance. We don't envisage using hard compound tyres here because the weather is unlikely to be all that hot at this time of year. A high proportion of the corners are right-handers and that puts more strain on the left-hand tyres, so we could see some teams running a medium compound on the left and soft tyres on the right.

"Our GT1 partners will be able to choose between soft and medium tyres. The difference between the two is quite marked and each type performs better at distinct track temperatures. At the Nurburgring, for example, we saw that the medium compound was clearly superior at track temperatures of more than 30o.C, while the softer alternative came into its own below that temperature. The tyres our teams will have for Silverstone will be more suited to the faster corners but are essentially the same sort of product.

"Just as they did at the Nurburgring, our GT2 teams we will have a new commercially available tyre for Silverstone."

If it rains--

"Silverstone doesn't give much grip in wet weather. It becomes very slippery and aquaplaning can be a problem. Unlike Spa, where we had the possibility of running tyres for drying conditions, we recommend full wets for Silverstone, possibly even with extra 'cuts'.

"If the track stays dry, there is no big risk of making a mistake between the soft and medium compounds. Tyre choices in unsettled weather, however, could well influence the difference title fights."

Experience of the FIA GT Championship--

"Our involvement in the FIA GT Championship allows us to collect valuable data concerning tyres for GT cars at different circuits.

"This is notably the case at Silverstone which we have already visited this season, and where we have seen both wet and dry conditions. The information we gathered has helped our preparations for the British round of the Le Mans Series, and we have obviously extrapolated that information to adapt it to the LMP cars, too."

The Michelin Energy Endurance Challenge

The Silverstone round sees the 2008 Michelin Energy Endurance Challenge continue. This challenge is based on the fuel consumption of the cars as a function of their average speed. The winning crew of each race will be invited on the LMS podium to receive the Michelin Energy trophy. The

"Michelin Energy Endurance Challenge" championship leader is easily identifiable by the number "1" decal visible on his car.

-credit: michelin