Until today, I have yet to take my TCH on a decently long highway trip.

Going to my destination today, it was pretty much all highway without any traffic and I got 37 mpg (exactly the EPA estimate for highway). I probably could have done a little better had it not been for the hot weather which required using a decent amount of AC to cool down the interior.

On the return trip, there was a fair amount of traffic ... did a lot of rolling and slow cruising during these times. Surprisingly my mileage was much better at 42.5 mpg.

I just find it amusing that I get awesome fuel efficiency during heavy traffic when I'm either rolling or cruising in the low 20mph range.