THE Lotus-inspired Proton Impian four-door saloon is already one of the cleanest and most economical full-size family cars on sale in the UK market.

It has a CO2 rating of just 160.9 g/km, a combined fuel consumption figure of 42.2 mpg and reduced band D (£120) road tax.

The potential savings for anyone converting their Impian to also run on LPG are even greater. The even cleaner bi-fuel Impian has a band 4 emissions grading, exempting it from city centre congestion charges to be launched in London next March and by many other local authorities before the end of 2003.

Exemption from congestion charging that will cost London-bound company car drivers and private motorists alike £5 per day is just one of the cost and tax saving benefits of LPG, which reduces CO2 and other noxious emissions by at least 50 per cent.

The cost of refuelling with LPG at more than 1,300 filling points around the UK is about half the price of petrol and the government has demonstrated its commitment to a cleaner environment by placing a freeze of LPG fuel duty until 2004.

Equally good news for Proton owners is the eligibility of the Impian for a grant of 60 per cent under the government-sponsored PowerShift scheme towards the cost of LPG conversion. That means the system can be installed for less than £1,000. Proton's smaller Wira four and five-door range is also eligible for a PowerShift grant, with 50 per cent funding towards the cost of LPG conversion.

For more information about an LPG conversion, contact the LPG AutoCentre Network on 01202 686006 or by email at sales@lpgauto.com