Hi Bazzer

Have a look at the big brother of the Xfire , Slk 55 amg the book says 30 mpg i can get 28 mpg no problem , As long as i drive like me gran ,



Marting
On the hot engine subject do not forget heat raises , so the heat is still coming out the engine after you have stopped , Back in the day i had a Sunbeam Tiger V8 4.2 & that would boil the coolant after you have parked up & walked away .

Cheers

Andy (soon to be Xfireless )