In Europe it`s popular decision to spend less money. At first it concerns to old cars with big engines.
If you have, for example, e34 535iA. You want to use this youngtimer everyday and you don`t want to pay for 18-20liters/100km - LPG it`s good choice to pay less. 1 liter LPG usually costs 30-45% from Petrol price (1 liter).
Engine starts on petrol and after heating runs on LPG.
End else - LPG is more ecological friendly
P.S. LPG = Liquefied Petroleum Gas
Let`s talk about this alternative fuel! ;-)
It's still fossil fuel. Have you heard of what they are doing in Brazil with ethanol and plant based fuels? Dramatic reduction in pollution and dependence on foreign oil. Get a conversion done bud. I hope Europe follows in the same direction as Brazil and hopefully North America too.