But then why is LPG like 1/2 the price of petrol when it has ~90% of the energy?
LPG is around 26 MJ/l, around 70% the energy of diesel, or the other way around, a litre of diesel has 43% more energy in it than a litre of LPG.
Of course LPG duty is far lower (15.805p) compared with petrol and diesel's 57.95p. LPG's duty is 42p less (before VAT).



and then fell as low as mid 80s. Wouldn't it be lovely to have a drop like that now