wowie, thats pretty good for a heavy vehicle!
as i said, i have an xj and its about the same highway figures.
my other car is an 03 commodore station wagon, this vehicle seems to have about 14l/100 around town and the best i have got is a solid 7 on the hway (the engine goes very lean in cruise, but the throttle musn't move for a continous 30 seconds, however we never get this on the work run on the ipswich motorway!)
its also 500kg lighter though.
now all i have to do is to convince the wife that we should sell the c'dore (i love my xj) and get a vehicle that's similar to the vy in size and has leather seats...