IN THIS FEATURE Cleaning up the motor industry Injecting some sense into engines Less-polluting petrols One cylinder at a time Electric avenue Alt.fuels The regional response

Alternative fuels with more of a future are the so-called biofuels, derived from organic, sustainable sources rather than finite fossil-fuel stocks. These typically also burn more cleanly than conventional diesel and petrol. Basic low-tech diesel engines can use oils from a variety of sources - from byproducts of the food and catering industries to more refined substances obtained from rapeseed oil, sunflower oil or indeed, oils from a number of biological, re-growable substances. There are numerous anecdotes about drivers running their cars on filtered chip-shop waste oil and off-the-shelf sunflower oil in Britain alone, as well as motorists in more exotic climes using coconut, peanut or palm oils. Caution is advised if you fancy trying this out: modern diesel engines with complicated injection technology (as described above) aren't compatible with these relatively crude substances as yet - their complex electronic control systems can't cope - but the hurdles to overcome are fairly minor. It's similarly easy to convert petrol engines to run on alcohol-type fuels such as ethanol, popular in many countries and championed by General Motors, amongst others.

Some folks have even drawn biofuel from palm oil by pressing coconuts

Of some concern are ethical issues: notable environmentalists have pointed out that to substitute even a proportion of international fuel demand with biofuels, the land requirements to grow the crops to supply the raw materials are such that Third World countries could end up growing such crops at the expense of their own food needs, and at risk to damaging their local eco-system with such intensive farming. However, on a small scale, even using land which is currently set-aside under EU subsidy could produce significant amounts of fuel to offset the use of so-called 'dinosaur derv'. In the short term, biofuels are increasingly being used in a blend with conventional fuels. Whilst it's easy to take the view that the oil companies are just nasty global capitalist corporations sucking the world's natural resources dry and ruining the eco-structure in fragile areas, they do have a financial interest in environmental issues: they can't keep selling fossil fuels when they run out or it becomes less viable to extract them from inaccessible areas. This factor alone is likely to stimulate sustainable-source fuel development.