The Ridgeline's proposition is that it's the Honda of pickups, and shoppers might automatically think it's lighter and more efficient because of the brand's reputation. It fares about as well as some full-size pickups in fuel economy, but it's a smaller truck with less of the outright towing and hauling capability of those larger vehicles.
The EPA rates the Ridgeline at 15/20 mpg for its single drivetrain configuration--V-6 and four-wheel drive, coupled to an automatic transmission. It's about the same fuel economy you'd get in a base V-8-powered Chevrolet Silverado 1500, which tops the Ridgeline at 15/22 mpg. The V-6 Ford F-150 hits 17/23 mpg, though it may not be as quick as the Ridgeline.
Honda hasn't said whether it will offer a hybrid or diesel Ridgeline--or even if it will keep selling the truck beyond the 2011 model year.