FLEETS with the biggest incentives to convert their vehicles to gas, are sticking with petrol and diesel because of the lack of a viable gas refuelling infrastructure. British Gas itself has had to end its gas fleet policy - it operated around 300 vehicles - for operational reasons, after strategy changes meant the gas-powered vehicles could no longer meet its operational demands.

Until a convenient refuelling structure is in place, only bi-fuel vehicles capable of running on both gas and unleaded petrol are feasible, which poses logistical problems for fleets where maximising load space is an important consideration due to the space occupied by the gas tank.