It wasn’t so long ago that liquefied petrolem gas (LPG) was being touted as a viable alternative to petrol and diesel.

A favourable tax regime kept prices at around 40p per litre – that’s about half the price of unleaded – and it was seen as a greener fuel.

The Government offered grants towards the cost of LPG conversions, and half a dozen car manufacturers were offering official ‘factory’ conversions for their vehicles.

But a change of Government policy saw incentives to convert to LPG eliminated.

Now, with petrol costing more than £1 a litre and reports of diesel as high as £1.15, is it time to reassess the value of a used car with an approved LPG conversion?

Despite increases in the tax levied on LPG, I don’t recall seeing any filling stations where it costs more than 50p per litre.

There are still close to 1,300 LPG refuelling sites in the UK.

Historically, guide values for factory approved LPG conversions such as the Vauxhall ‘Dualfuel’ and Volvo ‘Bi-fuel’ have been the same as for petrol-only models.

But I think there would be an appetite among customers of used petrol models to pay a bit more for a ‘factory’ bi-fuel car. Subaru has introduced an approved LPG conversion to some Forester and Legacy models.

Perhaps the continuing rise in petrol prices has thrown LPG a lifeline.