The Peugeot pit stops were not as slick as those of the Joest team that had taken Audi to seven previous Le Mans wins but there was another factor working against Peugeot: swapping drivers.

The 908 is a fixed-roof coupe, whereas all but one of the other contenders in the LM P1 class were open cars. The driver struggles though the tiny door aperture – it is really just a window – with his tailor-made seat but there is no room for a crew member to reach over to adjust the safety harness and plug in the radio, transponder and drinks bottle hose.

The result is one of the most ridiculous images in motor racing. The crewman has, literally, to dive in through the window on the other side and make the connections with his legs waving in the air. Most Peugeot driver changes could not be accomplished in the time that it took to fuel the car or change the wheels. I don’t know how much the 2^nd place car lost this way but it could have been more than 4 minutes…

By 2010, unless the organizers change their minds, all LM P1 cars will have a fixed roof. The thinking is that coupes can be better optimized aerodynamically but against that must be the difficulty of extricating the driver in a serious accident.

But Le Mans cars are going to change before that. The Automobile Club de l’Ouest which runs the Le Mans race has accepted that its formula that seeks to bring equivalence to diesel and gasoline engines is wrong; diesels took the first five places in qualifying this year and held them throughout the race. Basically, the gasoline-powered Pescarolo and Courage teams didn’t have a chance.

The ACO has to be careful, though, because the Audi and Peugeot operations are the only big manufacturers involved in LM P1 and their dominance may not be entirely because they run diesels; it could be as much to do with big budgets and technical sophistication.

If they do fix the rules to give the gasoline cars a lift, Le Mans 2008 could go down as the diesels’ last great ride. I am not sure that would be a bad thing. These big diesel race cars are curious beasts. The drivers like them because of their power and generous spread of torque (700 bhp and 1,200 Nm for the Peugeot) but they don’t sound like proper race cars. In fact, they are so quiet that the loudest noises are aerodynamic, rather than from the exhaust pipe.

Diesels were not meant to do this. They are at their best at near constant speed and the advantages for road cars in terms of fuel consumption and low CO2 are not relevant on the track.

Motor racing is automotive performance art, and demands the lightest, highest-revving engines, developments from which trickle down into sportier road cars and eventually even small family cars. In the 1980s Nobuhiko Kawamoto, president of Honda, justified the extreme 1.5 litre turbocharged Formula 1 cars thus: ‘At their peak, these engines achieved 1 bhp per cc. Just imagine: that could mean a 100 bhp family car with an engine so small it could be hidden under the back seat.’ Such thoughts are beginning to be relevant today.

Sure, the racing diesels have particulate filters – demonstrating, if nothing else, their durability in severe use - and this year claimed to be using a proportion of bio-fuel combined with GTL (Gas to Liquid) fuel. That was window-dressing: the proportion of plant-derived material was admitted as ‘small’ and GTL is the most convenient starting point for the Shell chemists who formulate the diesel used at Le Mans.

Has the diesel engine gained in respect and popularity because of Audi’s hat-trick of Le Mans wins? Perhaps. Does Peugeot racing with a 5.5 litre V12 diesel do anything to persuade customers of the fuel economy advantages of their 1.4 litre four-cylinder diesels? I doubt it.

What motor racing in general and endurance events like Le Mans in particular do for a volume car manufacturer is enhance brand awareness and provide the glow of technical competence and a competitive spirit. Those benefits would be just as easily gained with proper racing engines – running on gasoline.

Image Gallery