We took our Prius from Philadelphia to Yellowstone Nat'l Park. Two weeks of driving, 5300+ miles on 10 fill ups of about 10 gallons each time. In fact, I filled up in Pittsburgh and am still driving around here at home on that tank of gas. Pretty much all of that trip was on interstate highways across the plains and up into the high mountains, and we still got close to or over 50 mpg. Our town mileage is even higher!
It's roomier than it looks. We carried a week's worth of camping gear and luggage for motel nights with room to spare. My 6Ɖ" husband and 6Ƌ" son are very comfortable driving this car. It's quiet, handles very well, and has lots of nifty gadgets for the base model, which is what we bought. The downside is that there is an 8-month wait for one in our area, and they just recently upped the price a few hundred dollars.
But we love it, and found it to be great on the highway AND in town.