It's only a few weeks from dealerships, but the 2013 Land Rover Range Rover doesn't yet have any official fuel-economy ratings, or blessings otherwise from the EPA.
Land Rover estimates that with the dramatic changeover in construction techniques, the new Range Rover sheds 700 pounds over the comparably equipped 2012 version. In the new Range Rover, it's not just the body panels that are aluminum--it's body sections, too, riveted and glued together with aerospace-level adhesives for ultra-rigid joinings.
The weight loss and other drivetrain improvements should boost the Range Rover's operating efficiency by about 9 percent, it's estimated. Against 2012 ratings of 12 miles per gallon city, 18 miles per gallon highway, and 14 mpg combined, that works out roughly to an estimated 13/20 mpg, or as much as 16 mpg combined. It's not a wonder of gas mileage, then--but it's much improved, and a good bit ahead of vehicles like the Mercedes-Benz GL 550 in that regard.
Unfortunately, it doesn't look like U.S. customers will get to experience the Range Rover with diesel power, at least until the middle of the decade when European regulations on emissions become much more restrictive, much more like our own. There's also a plug-in hybrid diesel coming to the Range Rover in other markets--perhaps it's possible, once those other hurdles are cleared.