On his 21^st birthday, Prince Charles's received an Aston Martin DB6 from his mother the Queen. Recently, in his quest to cut his personal carbon footprint, the Prince converted the vintage classic car to run on 100% bioethanol fuel distilled from surplus British wine. A nice white wine from a Wiltshire vineyard, to be precise.

The 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.

The vineyard 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 and made into bioethanol.