... to petrol engines too, with similar enhancements in fuel economy and emissions. Although the long-term future of the conventional petrol/diesel engine may be bleak, such efficiency gains limit their impact on natural resources and the environment until replacement technology can be introduced. Another route to fewer emissions is gas. Offered as a factory-fitted option by Vauxhall (Dualfuel), Volvo (Bi-Fuel) and many others, Liquid Petroleum Gas (LPG) is cleaner than petrol, far cheaper and ever easier to obtain. Meanwhile Compressed Natural Gas (CNG), although requiring heavy pressurised storage containers, is not reliant on crude oil, is readily available in the UK's (it's the same as domestic gas) and is again clean and environmentally-friendly. It's an easy way to make a different. None of these alternatives really solve the problems of reducing fossil fuel stocks, although Bio-Diesels, produced from harvested crops, may ensure that diesel engines outlive their petrol counterparts. To look further ahead ...

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