Text 9 Want to Drive Green?

Onе way to save fuel and be kinder to the environment is to drive a smaller car. Or you can buy a hybrid, which is also cleaner and meaner with pet­rol by using a combination of an internal-combustion engine and an electric motor. Then there are all-electric cars that don't use any petrol at all, and hydrogen-pow­ered ones, some of them using fuel cells. And increas­ingly there will be variations in between. Picking a new green drive in 2009 will not be an easy decision.

For a start, the choice will be much bigger. Plug-in versions of Toyota's Prius hybrid will allow that ground­breaking vehicle to be charged from a mains socket. But it will face tough competition from a new Honda Insight hybrid capable of 80mpg or more. Watch out too for a new six-seater Renault hybrid and a four-wheel drive Citroen with a diesel engine powering the front wheels and an electric motor operating the rear ones.

Other fuel-saving cars will appear at motor shows. General Motors will also start road testing the Chevy Volt before it goes into mass production. The Volt is a compact plug-in hybrid able to travel on a full charge for about 40 miles (64km) – a typical daily commute – but with a small petrol engine kicking in as a range-extend­ing generator thereafter. It will cost around $30,000.

Better batteries will give electric cars a boost. Some already leave petrol ones in the dust – at a price. The Tesla Roadster, based on a British Lotus, uses a power-pack of more than 6,000 beefed-up versions of the lithium-ion batteries found in laptop computers. It can accelerate from 0-60mph in under four seconds and reach around 125mph. It is already on sale in California; Europeans will be able to get their hands on one in 2009 – at around €100,000 ($140,000). If you do not mind 0-60mph in eight seconds and one less wheel, then zap, a Californian maker of electric vehicles, will offer a sleek three-wheeler called Alias for around $32,000. Classed as a motorcycle, it resembles a souped-up Reliant Robin.

More hydrogen-powered vehicles will arrive, but remain constrained by a lack of refuelling stations. Not so for petrol and diesel cars, which will be getting bet­ter, too. Fiat’s new Multiair engine will start appearing in its cars. These engines use hydraulics and electronics to optimise valve settings. When combined with a tur-bocharger, this will allow tiny two-cylinder engines to perform like four-cylinder ones, but use 20% less fuel.

With such tricks, some small petrol and diesel cars will be able to achieve around 80mpg – and, with a light foot on the accelerator, break 100mpg. But big cars will become more frugal too. A new Daimler engine will op­erate as a petrol engine when power is needed and like a diesel when economy is required. Daimler has called it the DiesOtto after two German engineers, Rudolf Die­sel and Nicolaus Otto. The internal-combustion engines they helped to pioneer may be more than 100 years old, but they have yet to reach the end of the road.