The Silverado/Sierra XFE includes the aluminum version of the 5.3L V-8, with Active Fuel Management (cylinder deactivation) and the six-speed automatic. It's lowered about 10 mm in the rear and has the hybrids' lower front-spoiler and front airdam, plus low rolling resistance17-in. aluminum wheels, aluminum lower control arms, and soft tonneau cover. Rear-axle ratio is 3.08:1, and GM claims a best-in-class drag coefficient of 0.412. While the aluminum-intensive mass savings of about 150 lb places the GM twins in a lower weight category, they don't lose any truck capabilities, GM says, with towing capacity up 400 lb to 7000, because of the six-speed and a high-capacity cooling package.

GM also added a hydraulic rear body mount, which helps improve the ride over rough roads, especially expansion-strip highways. Ditching 20-in. wheels for 17s doesn't hurt ride quality, either.

The XFEs have plenty of smooth power for most truck owners, at least those who don't need to make a statement (the Denali's 6.2L engine has been extended through Chevy and GMC's ranges for those who do). The XFE badging is even more subtle than hybrid badging, but it's added only because the EPA won't let automakers show a higher fuel-mileage sticker for options, like the separate items that boost these models' fuel economy, alone.

With the hybrid and XFE models, GM is working hard to keep the V-8 alive. Unlike with midsize cars, in which buyers are now leaving the V-6s behind for four-cylinder engines, there doesn't seem to be much movement from V-8 trucks to V-6 trucks, yet. Truck buyers are looking to save money in this economy, though: Traditionally, crew cabs took more than 40% of Silverado/Sierra sales, with less than 40% for extended cabs and 20% for standard cabs. Last month, the mix was an even 40/40/20.

Indicated (on-board computer) fuel mileage for '09 Chevy Silverado short drives:

LT extended cab with 5.3-liter aluminum V-8, AFM, six-speed automatic: 14.2 mpg on city/highway mix of approximately 15 miles.

XFE crew cab: 16.3mpg (on same route as above).

Silverado Hybrid: 21.7 mpg (on shorter, eight-mile city-only route).

Base price $32,000 (est) $39,000 (MT est)
Drivetrain Front-engine, RWD Front-engine, RWD/4WD)
Engine 5.3L/320-hp/340-lb-ft OHV 16-valve V-8 6.0L/332-hp/367-lb-ft OHV 16-valve V-8 plus 81-hp/184 lb-ft elec motors
Transmission 6-speed auto 2-mode CVT/4-speed auto
Curb weight 5400 lb (MT est) 5400 (MT est.)
Wheelbase 143.5 in 143.5 in
Length x width x height 230.0 x 79.9 x 73.4 in 230.0 x 79.9 x 73.8-74.0 in
EPA city/hwy fuel econ 15/21 mpg 20-21/20-22 mpg
CO2 emissions 1.1 lb/mile 0.9-1.0 lb/mile
On sale Late 2008 Early 2009