I would say it depends entirely on which model. Whilst I accept it would be virtually impossible in an early 2 litre Series One, reckon in a later Series I, II or III I it would be perfectly okay. I personally owned a Lightweight IIA for a number of years, and I know that excellent 2.5 petrol engine would have eaten up the kilometres no problem at all – it was an amazing vehicle.
All other Land Rover models are eligible (and suitable), that’s if you can afford the fuel for a V8-powered RR Classic or 101FC! Then again, I suppose that’s why they invented LPG.