General Motors is building on the fuel economy of its full-size pickups and SUVs with new XFE models of the 2009 Chevy Silverado, Chevy Tahoe, GMC Sierra and GMC Yukon. The vehicles use a combination of mechanical, aerodynamic and mass-reducing enhancements to deliver a 5-percent increase in EPA-estimated highway fuel economy and more than 7-percent improved mileage in city driving.

The aero enhancements give Silverado XFE and Sierra XFE models a 0.412 coefficient of drag (cd). The pickups join the Tahoe Hybrid and Yukon Hybrid as the most aerodynamic full-size SUVs at 0.349 (cd).

The new XFE — Xtra Fuel Economy — models reflect GM's quick adaptation to an evolving market that remains a very important segment. They are available on 2WD vehicles equipped with the 5.3L V-8 and six-speed transmission. They achieve 15 city and 21 highway mileage ratings versus comparable non-XFE models' 14/20 ratings. Most importantly, the increased efficiency does not come at the expense of capability. Towing ratings for the Tahoe and Yukon are unchanged, while the Silverado and Sierra increase from 6,600 pounds to 7,000 pounds due to the new, six-speed transmission and high-capacity cooling package.

“We are pulling out all the stops to deliver a more efficient package for customers who need the capability of full-size pickups and SUVs and want the very best fuel economy,” said Gary White, GM North America vice-president and vehicle line executive for full-size trucks. “Our pickups and SUVs are the fuel economy leaders of their respective segments, but our engineers knew greater efficiency was achievable. We fast-tracked the XFE models to get them into dealer showrooms as quickly as possible.”

All models carry the XFE name badge and are offered in the LT trim for Silverado and LS and LT trims for Tahoe. Sierra XFE comes with SLE trim and Yukon XFE is offered with SLE and SLT trim. Most regular-production options for all models are available. Silverado XFE and Sierra XFE are offered in 2wd crew cab body styles only.

“In addition to the XFE models, GM already offers hybrid versions of the Tahoe and Yukon that achieve up to a 50-percent improvement in city fuel economy and coming in the first half of 2009 are the Silverado and Sierra Hybrids,” said White. “These hybrid pickups offer up to 25 percent overall increased fuel economy and greater than 40-percent improved mileage in city driving.”

GM's more efficient full-size pickups and SUVs are powered by a 5.3L FlexFuel V-8 (LC9) engine that's built with a mass-reducing aluminum cylinder block and heads. It is rated at 320 horsepower and 340 lb.-ft. of torque in Tahoe and Yukon and 315 hp and 338 lb-ft in Silverado and Sierra.

The engine is backed by a Hydra-Matic 6L80 six-speed automatic transmission (with high-capacity cooling on Silverado and Sierra).

A rear axle equipped with a fuel-saving 3.08 ratio is also standard on all XFE models. Lightweight aluminum wheels and low rolling resistance tires (with higher tire pressure) also are included on all models.

Other unique content and features for Silverado XFE and Sierra XFE include:

  • Soft tonneau cover (improves aerodynamics).

  • Extended front lower air dam

  • Lowered suspension and revised chassis tuning (improve aerodynamics).

  • Aluminum lower control arms (reduce mass).

  • Aluminum spare wheel (reduces mass).

  • Seventeen-inch aluminum wheels (reduce mass).

  • Automatic locking rear differential.

  • Trailering package.

  • Low rolling resistance tires.