Only a tiny fraction of Northern Ireland's vehicles run on gas and its wider uptake is hampered because the fuel is still not readily available, figures suggest.
Latest figures from the Department of Energy show that of 740,000 cars, only 0.04% run on gas, gas bi-fuel (those which can run on petrol or gas), or gas diesel.
Only eight lorries and 11 vans are registered as using gas-based fuel which is more energy-efficient than oil-based ones.
Tom Elliott, Ulster Unionist MLA for Fermanagh and South Tyrone, said: "I believe there is an opportunity for major economic savings and environmental benefits by using gas-powered vehicles."
The MLA said that the figures were shocking, as gas costs 40p per litre, which is less than half the price of petrol or diesel.
Admitting that he too was forced to use petrol as filling stations did not stock gas fuel, he said: "I would hope that in light of these figures becoming known, the DoE would look into how they could help stimulate the use of gas fuel in vehicles."
Copyright © Press Association 2009