Ford Focus 1.8i 16v Bi-fuel Ghia

With the huge discount on offer, along with the tax benefits and fuel savings, now is the time to buy a Bi-fuel Focus. There is no noticeable performance difference between this and the petrol car, while boot space isn't affected - all you lose is the spare wheel.

Ford's current Focus is feeling the pressure. Although the family favourite is still riding high in the sales charts - it has been Britain's best-selling car for the past 39 months - there's one area in which its fiercest rival has it soundly beaten.

A cheap-to-run LPG edition of the Vauxhall Astra has been on sale since June 1998, leaving the blue oval trailing. So now Ford is playing catch-up, which is great news for buyers on a budget.

Until the beginning of September, the firm is offering a new Bi-fuel (an LPG and petrol hybrid) version of its Focus for the same price as a standard petrol model - that's £1,990 less than the £15,990 list price of this Ghia.

You'll have to be quick to take up the offer, but the saving's worth having as it means private buyers can enjoy all the benefits of LPG without forking out to have their current car converted.

Better still, this Focus has passed a series of stringent crash tests and comes with a full three-year, 60,000-mile Ford warranty. We jumped at the chance to drive it, and were impressed by the 'completeness' of the conversion.

With the exception of a discreet badge and the extra fuel nozzle for the LPG, there's little to distinguish this car from any other Focus. The same is true of the performance on the road. Flipping between petrol and LPG while behind the wheel of this 1.8 Ghia made little difference to our rate of progress.

To switch to gas, you press a button next to the handbrake. There's a click from the tank in the boot, a dash light comes on and the fuel gauge zeros, before resetting itself. It's certainly smooth. With a 55-litre petrol tank and a maximum 45 litres of LPG, drivers get a total range of more than 700 miles.

To cope with LPG, engineers had to harden the valves, fit new injectors and do some replumbing, the most obvious bit of which sees the spare wheel in the boot floor replaced by the LPG tank and a can of tyre sealant and compressor.

Be warned, though - there's still no guarantee that LPG will remain a tax-friendly alternative to petrol and, in our experience, fuel stations that stock the gas can be difficult to find.

However, for high-mileage drivers, the Focus makes sense, as LPG is cheaper in the long run than diesel, despite returning 26.9mpg to derv's 51.4mpg. Added bonuses include exemption from congestion charges and lower road tax.