Originally Posted by 
sheerluck
				 
			Mike, my memory of the legislation in the UK was effectively anything that could be chucked in the tank of a vehicle to power it could be considered a fuel, and was therefore expected to incur fuel duties at the appropriate rate. I remember stories on the news of people being busted for dodging the tax, for home brew biodiesel, being pulled over by a copper if their car smelt of fish and chips.....
Ok, so it was a few years since I left there, and things may have changed, but the world of excise collection normally does not.