My sister drives a 2002 Highlander v6 2wd. I drove her car for a week while she was out of town and fell in love with the car-like ride and utilitarian flexibility of an SUV. That experience was the reason why I got a 2006 Hy Highlander.

When I was driving her car, I remember getting 18 mpg in mixed driving. I drove a long haul to Galveston (roughly 70 miles of freeway) and got 25 mpg. That is pretty average mpg for a v6 vehicle for its weight, probably on the high end for other SUVs in the same class.

For comparison's sake, my mom has a v6 Avalon and she gets 21 mpg in mixed driving. When I drive it (since I now have the skills to drive for maximum fuel efficiency) I can get 23 mpg. This also does make the point that one can make substantial efficiency. gains just by modifying technique, not just by buying a hybrid.

My Hy Highlander gets 25 mpg in mixed driving. Freeway-like driving on gently rolling terrain at moderate speeds (40-55mph) sees 33-37mpg.

Overall, almost a 40% improvement in mpg, of course your mileage may vary.