Lpg is a wonderful alternative fuel for cars and vans. The main advantage for most people is the fact that it is approximately half the price per litre of petrol. The vehicles are normal petrol engine vehicles which have been converted to use LPG. Sometimes this is done by the vehicle manufacturer or converted by a specialist company. LPG has a high octane rating and low levels of volatile compounds. This means that they burn more completely and so reduce pollution and reduce stress on the engine and extends the life of the engine. These vehicles can usually run on petrol as well as gas and start on petrol and then automatically switch to gas once the engine is warm.
You do need to use a specialist filling station but there are many in this country. You connect the vehicle to the pump by a high pressure hose and then just wait for the tank to fill. This takes about the same amount of time as filling a petrol car.