2009 GMC Sierra Hybrid to debut at Chicago Auto Show

Hybrid full-size pickup sees up to 40% gain in fuel economy

General Motors' recently released hybrid-electric system for full-size trucks, recently debuted in the Tahoe and Escalade SUVs, continues its inevitable march through the truck portfolio with the introduction of the 2009 GMC Sierra Hybrid, set to break cover at the Chicago Auto Show next week.  

Like the Tahoe, the Sierra Hybrid takes advantage of GM's new two-mode hybrid system to boost fuel economy up to 40 percent, in a vehicle that can certainly use it.  The Sierra Hybrid can operate in a fully electric mode at speeds up to 30 miles per hour, by virtue of a 300-volt nickel-metal hydride Energy Storage System.  Additionally, its 6.0 liter V8 uses Active Fuel Management to shut off cylinders when the extra power is not needed.  This allows the full-size pickup to operate in a fuel-saving four-cylinder mode in low-load situations and still bring the V8's full power to bear should the Sierra Hybrid's full 6100-lb towing capacity be needed.  The hybrid system's battery pack lives behind the rear seat, and the system has been tuned for minimal noise.
The Sierra Hybrid is available with two- or four-wheel drive, and only as a Crew Cab.  StabiliTrak stability control, side-curtain airbags and a trailer-towing package are standard on all Sierra Hybrids.  An electric air conditioner compressor and electric power steering ensure that the Sierra Hybrid is fully functional even when the gasoline engine is shut off, correcting an oversight that drew criticism in GM's last attempt at a full-size hybrid pickup.  

The Sierra Hybrid goes on sale during the fourth quarter of 2008, and joins hybrid versions of the Chevrolet Tahoe and Cadillac Escalade is bringing a measure of fuel efficiency to General Motors' full-size truck lineup.

Source: General Motors
Published Feb 4th, 2008 12:35am By Chris Jackson

CHICAGO - GMC announced the 2009 GMC Sierra Hybrid, a powerful full-size pickup that achieves 40-percent greater city fuel economy and a 25-percent improvement in overall fuel economy while delivering the capability expected of a full-size truck - including a 6,100-pound (2,767 kg) towing capacity.
Partnering General Motors' patented two-mode hybrid system and a powerful 6.0L gas V-8, the Sierra Hybrid delivers highly efficient performance, including all-electric driving up to 30 mph (48 km/h). That allows fuel savings to be realized even when the truck is fully loaded or towing a trailer.
"The Sierra Hybrid represents GMC's commitment to engineering excellence, delivering a fully functional truck that offers a significant improvement in fuel economy," said Jim Bunnell, GMC general manager. "Sierra Hybrid will deliver fuel economy that is expected to be the best in the full-size pickup segment, exceeding the current mileage leader - the non-hybrid Sierra."
The Sierra Hybrid goes on sale in the fourth quarter of 2008 and is based on the strong and capable Sierra platform that was introduced for the 2007 model year. It will be offered in the Crew Cab body style on both 2WD and 4WD models. Each model is equipped with several standard, popular features, including StabiliTrak electronic stability control system, a locking rear axle and a trailering package. Sierra Hybrid also offers dual-stage frontal air bags and head curtain side air bags, and it is the only full-size truck with five-star side-impact ratings in federal crash tests.
Hybrid details
The Sierra Hybrid's fuel-saving performance is derived from GM's advanced Electrically Variable Transmission (EVT) and 300-volt nickel-metal hydride Energy Storage System (ESS), which work in concert with the standard 6.0L V-8 gasoline engine with Active Fuel Management (AFM) and late intake valve closing (LIVC) technology. GM's hybrid technology system not only enables the Sierra to launch and drive up to 30 mph on electricity alone, it also allows the Vortec 6.0L V-8 engine to operate in its more economical V-4 mode for longer periods.
As part of the vehicle's emission control system, the ESS is warranted for eight years/100,000 miles.
With GM's two-mode hybrid system, the electric power used to propel the vehicle is generated by the hybrid system itself. When the brakes are applied or the vehicle is coasting, the electric motors within the hybrid system create electricity that is stored in the 300-volt battery. This stored energy is used to move the vehicle and the regenerative braking cycle is renewed.
The two-mode hybrid system provides seamless, dependable power on demand in an efficient package. In fact, its electric motor is less than half the size of those in single-mode hybrid systems. This technology was developed and is still used in fleets of hybrid transit buses in more than 70 North American and European cities. Scaled-down for use in passenger vehicles, the two-mode system delivers fuel savings where it is needed most - in large vehicles with high levels of capability. The two-mode system was first introduced on the 2008 Yukon Hybrid. It is a core part of GM's energy diversity efforts, which are centered on reducing dependence on petroleum, improving fuel economy, reducing emissions and minimizing the automobile's impact on the environment.
With the fuel savings of the hybrid system and Sierra's 26-gallon (98-liter) fuel tank, the Sierra Hybrid has a cruising range of more than 500 miles (800 km).
Quiet and smooth
Integration of the hybrid system on the Sierra is seamless - the battery pack is located beneath the rear seat - and perceptible only in what it lacks: noise.
"The Sierra Hybrid is exceptionally quiet," said Mark Cieslak, vehicle chief engineer. "From a passenger's perspective, the refinement of the hybrid system is quite evident throughout the driving experience, and showcases itself when the vehicle is moving under electric power."
Contributors to the quiet driving experience include:
* New exhaust system and resonator tuned for the 6.0L engine's Active Fuel Management operation
* Additional engine intake induction tuning for reduced interior noise and pleasing sound quality
* Low-rolling resistance, "quiet-tuned" P265/65R18 tires for reduced road noise
* Electrically driven 300-volt air conditioning compressor reduces vibration and allows the standard, tri-zone HVAC system to cool the passenger compartment even when the gasoline engine is shut off
* Electrically driven 42-volt variable-assist power steering reduces vibration and provides up to a 0.5-mpg fuel economy improvement by reducing parasitic losses common in belt-driven hydraulic systems
* Energy Storage System (ESS) cooling system internal fan is tuned to be quiet at low vehicle speeds when the fan could more easily be heard by the occupants
Along with quietness, the Sierra Hybrid also delivers exceptional driving smoothness, thanks to specifically tuned shocks for its Z85 suspension and a new hydraulic body mount. Located on the passenger side of the chassis, the hydraulic mount provides a dramatic improvement in highway driving smoothness, particularly on rough or choppy road surfaces.
"The hydraulic mount makes a dramatic improvement in ride quality," said Cieslak.
Additional details specific to the Sierra Hybrid include aerodynamic aids. A slightly deeper front air dam and a tonneau cover for the bed reduce air drag, fostering maximum efficiency.
Trailering performance
In addition to increased fuel economy, the Sierra Hybrid's electrically variable transmission also provides tremendous trailering capability, enhancing driving smoothness and quality when towing. Electric drive is enabled up to approximately 30 mph (48 km/h), even when towing, allowing fuel savings when the truck is towing a trailer.
"Along with being very smooth, the EVT always provides abundant torque at all rpm levels for easy towing," said Cieslak. "It is particularly helpful on grades, as the EVT's greater ratio spread allows the engine to hold optimal rpm for smooth, steady performance, with no hunting between higher and lower gears."
The EVT incorporates grade braking and tap up/tap down shift control. It also benefits towing on curves or lower-speed back roads, as exceptionally smooth gear transitions eliminate the "shift shock" torque disruption that can occur during abrupt shifts, such as when slowing or braking.
In addition to the eight-year/100,000-mile warranty on the Sierra Hybrid's Energy Storage System, GM's Five-Year/100,000 Mile Powertrain Limited Warranty continues to make GM a better choice for customers. GM's coverage focuses on the complete ownership experience and includes other provisions that competitors do not offer, including transferability to the next owner, more complete coverage of parts, and coverage for new and certified used vehicles. In addition, GM offers complementary programs such as courtesy transportation and roadside assistance.

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Comments (4)

TJ\'sdaddy TJ'sdaddy
I cannot understand why, with the fule prices the way the are, GM hasn't come up with a diesel/hybrid instead of this 6 liter version? I know a small diesel has been tryed in the early 80's and tanked but times have changed. The new diesel is pretty quiet and the fule econemy of a small motor has been proven in the range rover so you would think a hybrid version of this would be very impressive. Please do not wait for the foren country's to come up with this first so we can follow AGAIN!!!!
Feb 11th, 2008 12:50am
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TJ\'sdaddy TJ'sdaddy
I would like to know why, with the fule prices the way they are the people at GM haven't come up with a diesel version of a hybrid instead of this 6 liter gas engin. It seams like with a diesel motor combined with battery power this vehicle would finally set a trend for unbelievable fule efficency.
Feb 11th, 2008 12:37am
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Joe_Limon Joe_Limon
from 50+ mpg - 15mpg depending on how it is being used. If you are city driving with no load, then the batteries will be running 100%... if you are highway driving, it will probably going through its 4 cylinder mode, giving you probably about 25-30 mpg... if you are pulling a tailor through the city... probably close to 15mpg
Feb 4th, 2008 9:18am
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joelynn joelynn
so exactly what mpg does this get?
Feb 4th, 2008 6:34am
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