The Magny-Cours challenge.

Renault driver, Fernando Alonso currently leads the 2005 drivers' championship by 22 points. Heading into the second half of the season he will be keen to maintain his lead and get back to winning ways.

What will he need to do at the French GP this weekend? Over to his chassis race engineer, Rod Nelson to explain the specific challenges of round ten...

"In contrast to Montreal and Indianapolis, Magny-Cours is a circuit that demands relatively high levels of downforce - there are several high speed corners where good aerodynamic grip is important," he noted.

"Indeed, while removing downforce might improve straightline speed, the loss of grip in turn 3 - which precedes the long back straight - is such that you actually gain very little speed overall on the straight, owing to the slower cornering speeds.

"In terms of how we set the car up, the settings are quite stiff, and ride heights are low as the circuit is quite smooth - this means we can use stiffer settings without compromising traction or braking stability. Furthermore, the stiff set-up helps the cars get a good change of direction through the high speed chicanes of turns 6/7 and 11/12 - the car can be quite nervous in these corners, although you cannot make up a lot of time here because both corners are followed by braking into slow speed corners.

"Magny-Cours is renowned as a circuit where grip levels are largely dependent upon circuit temperature. Situated in the heart of France, the circuit is subject to continental type weather conditions - and we see more extreme temperature variations than at most other circuits. This means that there is an increased possibility of having to use our tyres outside their optimum working range as the circuit temperatures fluctuate, which could potentially leave us battling graining or blistering depending on whether conditions are too cold or hot.

"The circuit configuration is also an important factor for the engineers at Magny-Cours. Turn 8 is the only left hander on the circuit, which means that the front right tyre is inevitably cold relative to the other three. The consequent loss of grip invariably causes understeer that the drivers must contend with.

"Secondly, the final chicane features very high, aggressive kerbs - and the overall lap-time is very sensitive to how these kerbs are taken. While the drivers will use them to get optimum lap-time in qualifying, they may be called on to modify their lines in race conditions, sacrificing lap-time for reliability. Indeed, the manner in which they negotiate the chicane in qualifying is also important - taking the correct line through the chicane on your out-lap can gain you straightline speed across the start-finish line at the beginning of the qualifying lap.

"Finally, if rain does play a part in the race weekend, the section between turns 13 and 17 may prove problematic. When this section was introduced two years ago, the new tarmac had big problems with standing water as the 'closed' surface of the new tarmac meant it drained very poorly - which made the decision of when to use dry tyres a very difficult one, because this section of track stayed wet much longer than the rest of the circuit. This characteristic should improve year by year as the tarmac naturally 'opens up' to allow better drainage, but if rain plays a part in the race, this may be an important factor to take into account."