See also driving 15 minutes to a fuel station with 2p less a litre (guilty as charged - human psychology is weird)Watch the pennies and the pounds look after themselves.
It is kind of funny that we care about a few quid for 4500 miles approx useage yet we all no doubt spend the savings on lots of really "useful" stuff. I am guilty of it as well. I probably used up any saving with my heavy right foot when travelling to Paris yesterday.