Yep. For comparison, I get 26-31mpg highway in my 300hp/330tq, 3.4 setup 00 Regal GS

City, I get as low as 19mpg, and that's with WOT at least 2-4 times a day.

The 04 GTP which is stock gets 24-27 Highway and 20mpg city, same type of driving.