750 mi, 11 hrs, 46.2 mpg

Well, I just took my prius on it's first long trip today. Wash, DC to Cleveland and back. 750 miles, running at right around 75 mph +/- 10. That trip just doubled the mileage on my car! Round trip took 16.25 gal of fuel, for 46.2 mpg calculated. For driving reasonably fast through the mountains, I am very happy.

I didn't exert any special effort to economize, other that I did try to accelerate slowly. As much as possible, I tried to keep it from downshifting when speeding up, which worked out to 1-2 sec per 1 mph increase. But when you're just speeding up from 65 - 70 or 75, who cares if it takes 10 sec, as long as no one's coming up on you?

I took one pit stop on the way over and non-stop on the way back, running 87 octane, and A/C set to 74 deg. auto. I used the cruise control on the ohio flats, but I did the mountains myself. The computer said 49.1 mpg

FWIW,
dave.