The original track was dominated by the 1.8 km long Mistral Straight that is followed by the high-speed right hand Signes corner. The long main straight and other fast sections made the track very hard on engines as they ran at full revs for extended spells. Engine failures were common, such as Ayrton Senna's huge crash during the 1985 French Grand Prix after the Renault engine in his Lotus failed and he went off backwards at Signes on his own oil and crashed heavily, with only light bruising to the driver. Nigel Mansell crashed at the same place in the same weekend during practice and suffered a concussion which kept him out of the race. Mansell's crash was the result of a slow puncture in his left rear tyre causing it to explode at over , which detached his Williams FW10's rear wing. The Honda powered FW10 holds the race lap record for the original circuit when Mansell's teammate Keke Rosberg recorded a time of 1:39.914 during the 1985 French Grand Prix. During qualifying for the 1985 race, Swiss driver Marc Surer clocked what was at the time the highest speed recorded by a Formula One car on the Mistral when he pushed his turbocharged, Brabham-BMW to . This compared to the slowest car in the race, the naturally aspirated Tyrrell-Ford V8 of Stefan Bellof which could only manage . Bellof qualified 9 seconds slower than Surer and 12 seconds slower than pole winner Rosberg.