ChillZ4 said:I think economy depends mainly on the different 3.0 engine. I have the 06 3.0si ED engine and have seen an average of around 44mpg when cruising at 70 on motorway. For a car with 265bhp and 44mpg is impressive! Always in sports mode!
I have a 2007 3.0si. 44mpg!! Are you pushing yours around?

Cruising on the highway results in a little under 9 liter / 100 km (31.4 mpg UK / 26.1 mpg US).