Spuggie, The Gubment have signed up to EU jurisdiction(for next 3-4 years IIRC) that says they can't increase the tax on LPG any higher PA than they increase petrol. so if Petrol goes up 1p then thats all LPG can go up. plus there is a scam that some people use in that the LPG you buy for heating can't have any tax imposed yet is exactly the same stuff, one home pump later and you have your own mini filling station
So irrelevant of how many take it up its still going to be cheap.