I just took my first real trip of any length in my T6. In 763 miles of driving I only used 30 gallons of fuel, for a 25.4 mpg average!
And this was with most of the highway travel at speeds of 80 to 110 mph, with a few blasts up to 130 or so. AND....about 1/4 of the total miles was in the Ozark mountains.

Needless to say, I am very, very happy with this car. I raced a Lincoln LS for over 20 miles, he stayed right on my ass the whole time, and each time we pulled out to pass cars, I'd stomp it and just walk away from him!
We got into a small town and stopped at a traffic signal, and this guy was just flabbergasted at the performance of the T6! He was very complimentary of my car, and gave me a big thumbs up when he turned off to go a different direction.

For just pure jaw dropping performance it is hard to beat my '93 RX-7, but for extended high speed cruising the T6 just is the ultimate vehicle.