Think of the hybrid option on '05 Chevy Silverado and GMC Sierra Extended Cab pickups as a minor mileage booster coupled with a major convenience. The boost is roughly 10 percent overall, "up to 13 percent" in city-only driving. On our 2-1/2-ton 4WD test truck (EPA ratings: 17 mpg city, 19 highway), we saw 15.3-16.6 mpg. The convenience is 20 amps of 120V generator power, much appreciated in hurricane-ravaged Florida, where GM sent 35.

Motivated by the same 295-hp Vortec V-8 and 4-speed automatic, the hybrids offer all the capabilities of standard trucks and drive almost normally. Braking to a stop, the engine shuts down (with a slight shudder) below 15 mph and stays down while your foot stays on the brake. Lift your foot, it restarts almost instantly. Jump quickly from brake to gas, you get a sudden surge of torque following a momentary hesitation.

The system's starter motor/generator is cleverly packaged between the engine and transmission without adding length to the powertrain. Its controller manages engine cranking, speed control torque control and torque smoothing/active damping through four flavors of electrical power (120Va.c., 14Vd.c. and 42Va.c. and d.c.) and recaptures energy to the 42V lead-acid battery pack through regenerative braking.

The hybrid option is $2,500, reduced to $500 (on our test truck) by a $2,000 discount--not bad for a built-in generator and slightly better economy on a fully capable pickup. Yet it could (and should) be much better with the new Gen IV DOD V-8 and a 6-speed automatic.

GM contends that large volumes of relatively simple and inexpensive mild hybrid trucks will save more fuel than small volumes of more complex full hybrid cars. True enough. But with maybe 5,000 available in six states, (Alaska, Calif., Fla., Nev., Ore. and Wash.) this year, where are the volumes?

COPYRIGHT 2004 Diesel & Gas Turbine Publications
COPYRIGHT 2004 Gale Group