The Drayson/Cocker Aston is one of three taking part prepared by Barwell Motorsport, but it differs from its stablemates in one respect. It has been modified to run on E85, a blend of 15% unleaded petrol and 85% bioethanol, and the victory is the first success by a bioethanolpowered car in any motor-racing series across the water.

The owner of this improbable green machine is Drayson himself, an engineer and entrepreneur turned Labour politician who, as Lord Drayson, now serves in the British government as minister for defence equipment. He grew up within earshot of Brands Hatch and was a frequent visitor. He acquired his first car, a green Austin Mini, shortly after passing his test but didn't take up racing until he was in his early forties, after the sale of his company in 2003. He took lessons in an attempt to catch up with those who had entered at an earlier age, treating the project almost as a full-time job.

By 2006, Drayson was competing in the GT Championship with a DBRS9 and, towards the end of that year, he began exploring with Barwell and Aston Martin Racing the possibility of participating in this year's championship in a car running on E85. A short period of intensive development funded by Drayson himself followed and the modified car was ready by midMarch. The main modifications involve the fuel system, which has to cope with the fact E85 is more corrosive than standard petrol. Unlike, say, Saab's BioPower road cars, the Aston doesn't exploit the higher-octane rating of E85 to produce a power boost; it is instead set up to mirror as precisely as possible the performance of the standard petrol car, a strict requirement for the Championship. In fact, the E85-capable car suffers the disadvantage of starting races carrying more fuel than its rivals because bioethanol delivers fewer miles per gallon.

So why was Drayson so keen to race a car using a renewable fuel?

One spur came from his children, who questioned why his car couldn't be "green" in terms of its environmental impact, as well as paint. Once the idea took hold, he saw the strong role motorsport might play in publicising biofuels.

"If you make it cool, people will want to go out and buy a bioethanol car." And it is clear that "making it cool" means not just taking part but winning, too.

Some of the biggest players in the industry share this faith. Audi and Peugeot have successfully raced diesel-powered cars at Le Mans, a development that has gone a long way towards helping diesels shake off their reputation for sloth. One thing is certain . . .

E85 certainly needs a boost if it is going to take off here and in the UK. Persuading customers remains an uphill struggle.

Finally, how did Drayson manage to combine his racing with a demanding government job? While it is difficult for him to find the time, the intense concentration driving requires allows him to switch off. He points out racing and the defence industry are both high-tech sectors, and it is clear he has been doing some thinking about how defence contractors might learn from the rapid development cycles in racing.

His immediate aim is to do as well as possible in this year's British GT Championship; beyond that he would like to compete in a biofuelled car at international races, including Le Mans. But, at present, the regulations do not permit E85powered cars to race there, so a