2009 Chevrolet Silverado XFE

Take the high road on fewer fill-ups

James M. Flammang / autoMedia.com

Fuel economy and big pickup trucks don't mix, especially with a powerful V-8 engine under that expansive hood. Or do they? Responding to concerns about gas mileage in its existing vehicles, General Motors is launching a series of XFE variants of several current cars and trucks. XFE stands for "Xtra Fuel Economy." One of those improved-economy models is the full-size Chevrolet Silverado XFE pickup. Silverado's corporate cousin, the GMC Sierra, also gets an XFE offshoot. So do the full-size Chevrolet Tahoe and GMC Yukon sport-utility vehicles.

Models, Mileage, Motor

Only one version of the Silverado will come as an XFE model: the two-wheel-drive crew-cab pickup, in LT trim, with a 5.3-liter FlexFuel V-8 engine and six-speed Hydra-Matic transmission. Like many GM engines these days, the FlexFuel V-8 can run on E85 (an ethanol/gasoline blend) as well as regular gasoline. GMC offers its Sierra XFE in the XLE trim level, with the same powertrain.

General Motors promotes a 5-percent increase in fuel economy for highway driving, and 7 percent in city use. Specifically, the Silverado and Sierra XFE trucks earns a fuel-economy estimate from the Environmental Protection Agency (EPA) of 15 mpg city/21 mpg highway. Both figures are 1 mpg better than those achieved by a regular Silverado or Sierra with a 5.3-liter V-8 engine.

GM also claims that the Silverado and Sierra XFE have the best aerodynamic traits in their class, with a drag coefficient of 0.412. That's a long way from the figures achieved by some passenger cars and sporty vehicles, but impressive for a big truck. A standard, soft tonneau cover promises improved aerodynamics. So do the extended front lower air dam, slightly lowered suspension, and revised chassis tuning.

In additional to better aerodynamics, Chevrolet credits reduction in mass for the fuel-economy boost, starting with the engine—a weight-conscious version of GM's 5.3–liter V-8 with an aluminum cylinder block and heads. Lightweight aluminum wheels hold tires with low rolling resistance and higher-than-usual air pressure. Aluminum lower control arms and aluminum 17-inch wheels also help reduce weight.

Built in Canada along with regular Silverados, the XFE was a relatively hasty development. "We achieved these improvements by kind of going into our parts bin," said Gary A. White, GM North America vice-president and vehicle line executive for full-size trucks. White claims the Silverado/Sierra XFE's 15/21-mpg EPA rating is the "best in the industry." For pickup trucks, White noted, fuel economy is now the Number Three purchase reason.

Power, Performance, Properties

Don't expect any shortage of power along with the gas-mileage increase. The XFE's reduced-mass V-8 delivers 315 horsepower at 5200 rpm, and 338 pound-feet of torque at 4400 rpm, running on regular-grade gasoline. Active Fuel Management can automatically deactivate certain engine cylinders under light-load conditions, as a fuel-saving measure. The XFE pickup's rear axle has a fuel-efficient 3.08:1 ratio.