Went for a wee smuggling run across the border this morning.
Petrol in the local garage here (N. Ireland) is 105p a litre. 11 miles away in the Republic it is 85.9p a litre. So all the locals drive across the border to fill up - and while they are there, fill a few jerry cans.
Two cans is quite restrained - the BMW beside us had 7 stuffed in his boot. Just drive very carefully on the way home.