Gas mileage may not be your first priority when shopping for a truly rugged SUV with outstanding off-road capability, but it's an issue if you're driving long distances off-road and on. The Nissan Xterra will disappoint in either case.
It's a stark reminder of how much gas you'll save by switching to a more efficient crossover vehicle, if that suits your needs. Take a Ford Edge with a turbocharged four-cylinder, for example--it's rated at 30 mpg highway by the EPA. The tough-as-nails Xterra? At best, the EPA rates two-wheel-drive models at 16/22 mpg. Add on four-wheel drive, and it earns EPA numbers of 20 mpg highway, and as low as 15 mpg for automatic-equipped versions.
Considering its mediocre fuel economy numbers, the Xterra is neither very fuel-efficient nor very green. And if you have passengers more often than cargo, there are plenty of far better, more carlike options.