The Highlander sets no fuel-economy records, but it's generally in line with other seven-passenger crossover SUVs.
The most frugal version of the Highlander, the four-cylinder model with front-wheel drive, doesn't fare much better than a Ford Flex with a V-6, though. The base Highlander's rated at 20 miles per gallon city, 25 mpg highway, and 22 mpg combined.
Highlander V-6s come with either front- or all-wheel drive. The front-drive model's pegged at 19/25 mpg, or 21 mpg, by the EPA. The all-wheel-drive version is rated at 18/24 mpg, or 20 mpg combined.
The most planet-conscious Highlander Hybrid fares much better, at least according to its EPA ratings of 27/28 mpg or 28 mpg combined. They're nearly identical to the prior Hybrid, though, and we've had trouble observing those figures in real-world driving.