Demand for ex-fleet diesel-engined cars is set to rocket in the next few years, Glass's Information Services predicts.

The automotive industry analyst says the boom will be fuelled by Government moves to increase Vehicle Excise Duty differentials in favour of diesel, making diesel a more attractive proposition for private motorists.

As a result of greater retail demand, diesel residual values would be expected to strengthen, counteracting the negative RV effect of a large fleet switch from petrol to diesel.

Bill Carter, editor of AutoProVision, Glass's future residual value forecasting system, said: “If the Government does what it has suggested in the past and increases the VED differential, this will have a profound effect on used diesel car sales.”

He added: “It may well be that there will be insufficient diesel cars being de-fleeted to meet the demand. Therefore we may not see used values of the latest generation diesels fall appreciably from their current levels.”