Fuel types: the pros and cons

Petrol

For: Petrol's main attraction is its availability. Petrol bowsers at service stations usually outnumber diesel and LPG bowsers by three-to-one or more, which means refuelling is quicker. Making petrol engines more efficient can deliver immediate and wide-reaching environmental benefits. BMW's latest technology, direct-injection, 3.0-litre V6 produces fewer emissions and uses less fuel than the small, four-cylinder Mazda3. Petrol produces fewer nitrogen oxides and particulate matter than diesel.

Against: Oil is a dwindling resource and petrol produces more greenhouse gases than diesel or LPG. The price of petrol is likely to keep rising as reserves dry up. It is not as efficient as diesel and it contains carcinogens such as benzene. Crude oil spills can have disastrous environmental consequences, while petrol spills have been known to contaminate ground water supplies.