I have a 2006 6-6 HFP Coupe.

I will get 30 miles per gallon on 93 octane BP. It has gone as high as 32 mpg.

The car performs really very well and there really isn't a lot I can complain about.

There is also a 2006 6-6 Sedan in the family. It seems to get 26-28 mpg on 89 octane BP and won't go better than that. I guess it has to do with the extra weight it carries compared to the Coupe.