Juan Pablo Montoya was dominant in last weekend's German Grand Prix, but the former CART champion failed to finish the race, as his engine failed on the 25th lap.
The failure was only a few laps after a disastrous pit stop which saw the Williams pit crew attempt to refuel the Colombian's car, abort, switch to teammate Ralf Schumacher's refuel rig and finally get him on his way.
Schumacher felt that his efforts to save the engine were the key to his victory. ""Juan Pablo pulled away and I thought, 'You do what you want,' he recalled. "I had started to save the engine already, because I know how long and hard this race is. And it paid off in the end."
Contrary to Schumacher's assertion, though, the 30-second pit stop may not only have cost him his solid race lead, though, but also the entire race.
"The engine temperatures go to the limit here, but normally it should be capable of standing a long pit stop," said Dr Mario Theissen, BMW Motorsport technical director.
However, the situation was exacerbated by high temperatures, in the mid-30s, and a second start to the race, after Michael Schumacher's Ferrari failed at the first start, and Luciano Burti crashed into the German, somersaulting in the air and spreading debris all over the front straight.
Formula One engines do not have cooling fans, and depend on airflow to the side-mounted radiators for cooling. As a result, standing on the grid or in the pits on a hot day can quickly send the engine temperature soaring.
"It was very stressful to have the restart because the engines ran hot twice," Theissen explained. "This allied to the 30 seconds he was stationary in the pits, sending the temperatures up again, might be an explanation."
Worse yet, in retrospect, there was no need to switch fueling rigs, as the original setup was actually working correctly.
"The lights that come on down by the nozzle went off, but it looks as if the rig was actually pumping, so as it turns out we put far too much fuel in the car anyway," said Patrick Head, Williams technical director. "Thinking he hadn't got enough fuel, we actually swapped the rigs over and used Ralf's rig."
As a result, Montoya's car actually had excess fuel at the end of the pit stop, putting additional load on the engine, and ensuring that even if he had been able to continue, the additional weight would have kept him from being competitive for the remainder of the race.