OP,
what mode are you driving the car in? Normal? If so, give SPORT mode a try, without using the paddles first. It wakes up the car as does turning traction control off and then if you REALLY want to get daring, there is a way to COMPLETELY turn of traction control as well.
As of last Sunday morning when I went to top off the G70, which is what I do every Sunday morning right before food shopping,...Mobil 93 octane, $5.20 a gallon.
It used to cost me between 30-35 dollars at half a tank,. Now, it is over 45 bucks at the same level.