Hybrid Truck Demonstrates Better Gas Mileage
FOR RELEASE: May 22, 2001Hybrid Truck Demonstrates Better Gas Mileage And A Host Of Other Advantages, Without Compromises
DETROIT - You could forgive the customer for thinking of it as a 285-horsepower portable generator on wheels. GM's parallel hybrid pickup truck can help power a construction site or campground with its pair of 110-volt electrical outlets.
But it's also a fully capable V-8 powered pickup truck that can haul and tow just as much as its rugged gasoline counterpart. It just happens to get 10-15 percent better fuel economy and have these power outlets.
"This is a hybrid with a twist," said Tom Stephens, vice president, GM Vehicle Integration. "Unlike our competitors, who are looking to use the electric motor as a power assist on a small powertrain and giving up some utility to accomplish that, we give you all the acceleration, towing and hauling capability you've come to expect by using a truck V-8 engine. The energy captured through regenerative braking and being able to shut off the engine at idle, improves fuel economy by up to 15 percent."
"That means I can tow boats, haul a full load, climb steep grades -- all the situations that I buy a V-8 for, and still have improved fuel economy! This is aimed right at the sweet spot of the new hybrid market," Stephens said.
Based on the popular GMT-800 full-sized pickup, known to consumers as the Chevy Silverado and GMC Sierra, the hybrid truck features a 5.3-liter VORTEC V-8 engine, the same as the conventional versions of the truck. The hybrid propulsion package will be available as an option on GM's full-sized pickups beginning in 2004. Pricing is still being determined, although it is expected to be competitive.
This fuel-efficient, full-powered pickup fits with GM's strategy of introducing hybrid propulsion in large market segments and in vehicles that use more gas.
"We believe hybrids are going to make the most sense in higher fuel consumption vehicles, and that includes pickup trucks," Stephens explained. "If you do the math, you can see that we can actually save significantly more fuel converting a 20 mpg vehicle into a hybrid than a 30 mpg vehicle, especially if it's a vehicle that sells in high volumes, not a niche vehicle."
Instead of a conventional starter motor and alternator, the parallel hybrid truck features an innovative electric motor that is integrated into the drivetrain between the engine and the transmission. This provides starting power and the ability to generate electricity and saves weight and parts.
The 4.8 kilowatts of electricity generated by the system has plenty of potential uses: it may be stored in a 42-volt battery pack, used to support on-board electric accessories, or employed to operate power tools off the pair of 110-volt, 20-amp outlets in the cab and bed. GM has chosen to go with advanced lead-acid batteries to keep the size and cost of the 250 pound battery pack reasonable.
As more 42-volt systems and by-wire controls become available, this architecture can accommodate them. These 42-volt subsystems also tend to be smaller and lighter than their 12-volt counterparts, which will further improve fuel efficiency.
The parallel hybrid truck's power steering is run by an electrically driven hydraulic pump rather than the traditional belt-drive system. This innovation saves weight and parts. Similarly, the heating system is supplemented by an electric pump that keeps hot water circulating even when the engine is off. In cold weather, this innovation will save considerable fuel.
At a stoplight, the gasoline engine actually stops running, but most of the accessories continue working on stored electrical power. When the light turns green and the driver steps on the accelerator, the gasoline engine kicks in again.
The truck gets more out of each gallon of gas because of the engine start/stop function and regenerative braking, which turns the motor into a generator as the truck decelerates.
In addition to all of its environmental advantages, GM market research has found that consumers would welcome the hybrid's electrical power takeoffs as more convenient and functional than using a portable generator. They typically mention using the 110-volt outlets for running power tools, camping equipment and other recreational gear. Some consumers also indicated they'd like to connect the truck to their home during power outages.