If you're worried about fuel costs, get a diesel. x5/ml/tourag. My folks have the x5 diesel, average 10.5L / 100 while hauling ass everywhere. 800+ km per tank, and a tank is only $70. And it's diesel, which costs less than premium.
S52|ZF|TRM Coilovers 670/895|Staggered 18" 5's