Agree with everyone. Where I live is mostly 2 lane highways, more than enough power for quick passing. Especially when you need to pass multiple at once. I don't know what my average is since owning the car, but multiple times I have gotten 25 mpg cruising 75 mph on long trips. Only thing I dislike being a heavier person is the lack of properly positioned lumbar support in the seats. I find myself using a rolled up shirt or something to compensate for long trips. Also agree with the trunk having plenty of room, plus the amount of rear legroom even with the front seats all the way back.
2009 Liquid Red GT
Currently Enjoying : WeatherTech Floor Liners, Tein S. Tech Springs, Monroe PPV Shocks/Struts, SuperPro Polyelast Top Mounts, 19" Sport Wheels & Firehawk Indy 500 Tires, 18" GT Wheels & Continental DWS06 Tires, Subwoofer Wire Mod, Kayhan Audio Headunit, 35% Llumar Ceramic Tint, Morimoto 35W HID Kit
Soon to come: CTS-V 4 Piston Brembos, CTS-V2 Sedan Wheels