George Alexander, chief commercial vehicles editor at residual value expert Glass's, is unsure of the future. He said: 'The vehicles that come to market now do pretty well but we do have serious concerns over where values will head in years to come.
'It would only take a change in Government policy for the financial advantages of LPG to disappear overnight. The values of these vehicles would then slump. Also, diesel engines are becoming so clean that they are now not too far behind LPG.'
David Hill, senior editor of CAP Red Book, agrees. He said: 'Late plate alternative fuel vans have been good news at auction so far but how will they perform with 100,000 miles on the clock and in a condition associated with that mileage?
'The few that we have seen have performed poorly because of worries about the condition of the engine valves and so on. Trade and retail customers alike frown on a 100,000-mile petrol van. LPG or CNG would be non-starters.'