Prince Charles's Aston Martin is not only a vintage car, it's now running on vintage too.
A nice white from a Wiltshire vineyard, to be precise.
As part of cutting his carbon footprint, the prince has converted the 38-year-old classic car - a 21st birthday present from the Queen - to run on 100 per cent bioethanol fuel distilled from surplus British wine.
The Highgrove-based Aston Martin DB6, which clocks up just 480km a year - averaging 10 miles a gallon (about 4km a litre), or 4.5 bottles of wine for every mile.
At over $2 a litre, the bioethanol is only slightly cheaper than conventional petrol in Britain, but produces 85 per cent less carbon dioxide.
The grapes used for the prince's fuel have been fermented into wine on an English vineyard near Swindon, Wiltshire.
Its owners bottle all they can, but cannot produce more than their European Union quota. Rather than destroy the excess, the vineyard sells it to the Gloucestershire biofuels supplier Green Fuels, where it is distilled.
The green prince has introduced a raft of environmentally friendly measures at his homes, such as reed bed sewerage systems and woodchip boilers at Highgrove and Birkhall, his Scottish residence.
He even tries to have his cows fed on grass, not grain - to cut their flatulence, minimising their emission of the greenhouse gas methane.
* Reproduced with permission from Peter Svans at The Gurdies Winery