Motoring: Emission accomplished, as cars convert to gas

Thinking of switching to

a more environmentally friendly way to run a vehicle? You're not alone, as James Ruppert reports

John Prescott suffered a minor mishap when manoeuvring a zero- emission, solar-powered Honda at a meeting of European environment and transport ministers in Chester two weeks ago. But the deputy Prime Minister still had reason to be cheerful: he was also showing off his ministerial Jaguar Sovereign V8, which has been modified to run on environmentally friendly gas.

Tony Blair is also alleged to have opted for gas power on his Chrysler Grand Voyager. Even the Queen is having some of her stable of Rolls-Royce and Daimler cars modified to produce 70 per cent fewer exhaust emissions.

Local authority fleets are starting to switch to gas, too. Humberside police uses 20 converted Protons. In France gas is half the cost of petrol; 15 per cent of vehicles in Holland run on it. So if the great, the good and the EU are going for gas, how about the ordinary motorist?

Glass's Guide points out that, apart from the environmental benefits, there are big financial ones. The November 1996 budget reduced the duty on liquid petroleum gas (LPG) and compressed natural gas (CNG) by 25 per cent and the last budget froze road gas fuel duty at 10.78 per cent, while raising the cost of both petrol and diesel by 6 per cent. At the pumps LPG costs around 39p a litre whereas a litre of unleaded costs 68p.

CNG is largely methane, like the natural gas that is piped into our homes. To fleet users it costs about 43p per litre. In a car it is stored at high pressure in a heavy tank four times the size of an equivalent petrol tank.

At the moment the only new cars available with this system are Volvos. The pounds 22,930 S70 and V70 Bi-Fuels run on both petrol and gas. Overall CNG burns much more cleanly than LPG and also produces considerably less carbon dioxide. However, there are fewer than 20 CNG refuelling points in the UK, and although 60 or so government vehicles have been converted to run on CNG, LPG is the better gas option at present.

Commercial vehicles have been using LPG, which is similar to bottled butane camping gas, since the Seventies; there are more than 120 refuelling sites. Conversion costs for a petrol car average pounds 1,000, half of what it would be for CNG. Also, the 1998 Budget, which offered a pounds 50 road fund licence for "clean" vehicles, could apply to LPG users.

However, the lack of filling stations is a problem, and so is the need for a 85-litre propane tank which in a medium-size care takes up most of the boot space. There are performance penalties, too; engine power drops by up to 10 per cent and fuel consumption rises by a similar amount on older carburettor models.

However, with more modern petrol injection engines the reduction in performance is hardly noticeable, and any penalty in consumption is more than compensated for by the lower price. If you typically spend pounds 1,500 a year on unleaded, LPG instantly saves pounds 658. LPG also prolongs engine life and results in a cleaner, quieter engine.

If you want to buy a brand new LPG vehicle there is a Ford-approved conversion at pounds 1,595 plus VAT. Vauxhall is poised to launch dual-fuel versions of its Vectra and Omega 2.0 litre models at a projected pounds 2,000 premium. However, the most common way to acquire an LPG-powered vehicle is to have an existing car converted.

According to Alan Cole, senior editor at Glass's Guide: "Developing an LPG infrastructure is the first hurdle to be overcome before LPG cars become a viable alternative in the UK, and this is why the manufacturers' most recent offerings to this emerging market concentrate on dual-fuel examples. There is no doubt that the current lack of a viable gas refuelling infrastructure is slowing the take-up ... Massive investment is needed from fuel suppliers."

It is possible to rent a tank. Calor can put a 2000-litre tank in your drive for pounds 72 a quarter. Bulk supplies of LPG would then be around 20p per litre plus VAT. If you have gas pumped into your home for heat or cooking, there is no reason why you should not have a refuelling facility for your car.

That is something for the future. So even if Mr Prescott can't handle solar power, he must be relieved that gas guzzling now has a whole new meaning.

Equipment and installation: Taylor Motors (01733 553031); Marine Eco Power (01590 688644). Gas and dispensing equipment: Calor Gas (0800 992200); Flogas (01530 230352)

Gas: pros and cons

Advantages

Reduced fuel bills, lower exhaust emissions (particularly with CNG), longer engine life, lower servicing costs, potential road fund licence discount, facility to use petrol means that drivers need never run out of gas - the oil-based kind.

Disadvantages

Reduced power output, reduced economy, loss of luggage space, few filling stations, especially for CNG, cost of conversion.