Formula One makes a return to Spa Francorchamps for the ING Belgian Grand Prix on September 14-16 where Bridgestone's medium and soft compound dry Potenza tyres will face the longest and one of the most exciting circuits of the season.

The Spa circuit was not on the calendar for 2006 and since the last race there it has been both re-profiled and resurfaced to provide an additional challenge. The track, at 7km, features a diverse mix of corners, including the world famous Eau Rouge.

The medium and soft compounds occupy the mid-range of Bridgestone's 2007 Formula One tyre range and this combination has been used five previous times this season, in Australia, the United States, France, Germany and most recently at the Italian Grand Prix.

Spa was the location of a three-day all-team test in July when the weather was variable. This type of weather is common to the region and rain has been a feature of many Belgian Grands Prix, so Bridgestone's wet and extreme wet tyres will be at the ready.

The Belgian Grand Prix has been won on Bridgestone tyres four times since Bridgestone's participation in Formula One, with the first win coming in 1999 by McLaren Mercedes driver David Coulthard and the most recent with Ferrari driver Michael Schumacher in 2002. There were no Grands Prix at the circuit in 2003 and 2006.

What challenges does Spa present?
Kees van de Grint, Bridgestone Motorsport Head of Track Engineering Operations: Spa is extremely challenging as it is a very fast track. To the contrary of some other fast tracks, where the downforce loads placed on the tyres are lower because of low drag set-ups on the cars, here a higher level of downforce is applied. This means the tyres are placed under gruelling conditions with high speeds and high loads for almost the entire lap.

How difficult is making the correct tyre choice in a wet weather race?
KvdG: Wet conditions can change so quickly that it is very difficult to make the right call. We always calculate and present to the teams the conditions when you should change from the dry tyre to the wet tyre and then to the extreme wet, and vice versa, but in race conditions it is not so straightforward. We can control many things, and we have many computers, but the one thing that we can't control is nature.