Chevy Silverado Hybrid delivers 20-plus mpg in city and highway

May 30, 2009/Steve Tackett


Building a 5,263-pound full-size pickup that gets 20-plus miles per gallon in the city and on the highway (cruising more than 500 miles on a tank of gas), shows Chevy is serious about addressing buyers’ fuel economy concerns with its 2009 Silverado Hybrid.
Base priced at $38,020 plus $995 destination charge, the 2009 Silverado Hybrid crew cab short-box pickup showcases GM’s new 2-mode hybrid technology. It’s available in two- and four-wheel drive.
A 2WD Silverado Hybrid delivers an EPA estimated 21 mpg city and 22 mpg highway, which compares with to the 14/20 mpg of the Silverado equipped with the 5.3-liter V-8. Hybrid models with 4WD rate 20/20 city/highway mpg.
It’s difficult to give real-world fuel-economy figures for the Hybrid because driver habits play an important role in fuel efficiency. During a long highway trip, the Silverado Hybrid test-truck delivered the exact EPA-rated 22 mpg. Importantly, its 26-gallon tank is filled with recommended regular unleaded gas.
The system’s basic elements are a version of GM’s 6.0-liter V-8, delivering 332 horsepower and 367 lbs.-ft. of torque; a 300-volt nickel-metal hydride battery pack beneath the rear seat; and a pair of compact 60-kilowatt electric motors fitted within a four-speed automatic transmission that works in a fashion similar to a continuous variable transmission.
This sophisticated transmission performs a balancing act, deciding when to summon the electric motors into action or to bypass them.

It’s during city driving when the electric motors get their greatest workout.
Unlike some hybrids, there isn’t dead silence at start-up because the gas engine immediately kicks in. Let it idle for about 10 seconds and the system goes into Auto Stop mode, in which power sources temporarily shut down. Also different from some of the others, engine power is on when reversing.
As soon as you get under way, driver input determines the powertrain’s actions. Stomping the accelerator (and driving under load) summons both gas (all cylinders) and electric power; moderate driving habits usually dictates the engine runs solo; and slow, conservative driving may only require electric-motor assistance. Basically, hybrid mode 1 covers low-speed, light-duty driving and mode 2 addresses highway operation.
In fact, the Silverado Hybrid can tool around a neighborhood on electric power alone. Basically, during slow, steady-footed driving, the test vehicle maintains electric power until just short of 25 mph (GM reports up to 30 mph).
Coasting or deceleration/braking results in charging of the battery. Come to a dead stop and the system goes into Auto Stop Mode. If you can’t hear when the engine is shutting off (often the case in this big pickup’s well-insulated cab), then you’ll see engine shut off indicated on the Auto Stop meter incorporated with the tachometer.
An economy gauge with a green bar in the 12 o’clock position indicates when the driver is optimizing green driving habits. The goal is to keep the needle centered in the bar.
Driving Chevy’s “green” pickup doesn’t come at the sacrifice of grunt, with a 6,100-pound towing capacity for 2WD models and 5,900 pounds for 4WDs. The Hybrid’s 6.0-liter — as well as the non-hybrid Silverado 5.3-liter V-8 gas-engines — boasts the efficiency of Active Fuel Management displacement-on-demand. This technology offers major improvements in fuel economy via the ability to seamlessly switch back and forth from eight- to four-cylinder operation as driving situations demand.
A key benefit of a displacement-on-demand engine is that larger pickups purchased with towing in mind aren’t penalized in daily commutes, when they’re not towing. While highway cruising under load — passing, trailer towing, climbing hills — full V-8 power is used.
Along with adding dazzle, the 18-inch chrome-clad aluminum wheels provide a weight savings over the standard steel wheels

These are centered in low-rolling-resistance “quiet-tuned” P265/65R-18 tires, which help reduce road noise.
The Silverado Hybrid has excellent ride quality for a large pickup. A key refinement is a new hydraulic body mount in the No. 3 position, on the passenger side just in the back of the cab. A StabiliTrak electronic stability control system is standard.
Well-designed 40/20/40 split-bench seats also factor into passenger comfort. Folding from between the seatbacks is a massive lockable storage console with cupholders. A six-way-power driver-seat adjuster is available for $275. Cloth upholstery is standard and a leather upgrade is not available. The 69.3-inch short box is covered with a soft tonneau cover, which contributes to aerodynamics and fuel efficiency. A bed extender is a $299 option.

(Tim Spell is editor of the Houston Chronicle InMotion section.)

Copyright, Motor Matters, 2009