just got back from a trip to the french alps and averaged 44.7mpg over a good 7hrs 550 miles (1 pee stop and 2 tolls) journey with the cruise set at 82mph. Keeping it clean and polished up is good for 1-2mpg i reckon.
Back here though im getting an average of 49 - 52 on a 1.5hr commute. (50-70mph in traffic)