First Impression: 2009 Silverado & Sierra Hybrid Trucks
I had a chance recently to spend a little time in two new hybrid trucks, the 2009 Chevy Silverado hybrid and the GMC Sierra hybrid. I haven't driven GM's Yukon or Escalade hybrids (they're built with the same two-mode system) so I wasn't sure what to expect power-wise when I climbed behind the wheel of the Silverado.In three words, I was impressed.
GM's Hybrid System
The 6L trucks can run on four types of power:
- electric power
- V4 gas power
- V8 gas power
- a combination of electric and gas power
When the truck is in motion, a computer determines which of the four modes is best for the current conditions, making changes to optimize power and economy. After our road tests, I heard a couple of people say they felt the movement that occurred when the system changed from electric to gas power was annoying. I disagree, and thought the operation was pretty smooth and seamless, with no jerking motions between modes.
Power vs. Economy The hybrid system always attempts to balance power requirements with economy. For instance, if you're cruising along in V4 at a steady 60 mph, and you come to a slight grade, the truck's electric motor will kick in to increase power. Expect the system to tap-in to the more gas-hungry V8 when you need more power -- when passing, traveling up steeper hills or pulling a load.
Monitor Your Driving in Real Time A gauge on the dash helps you see how your driving habits affect the truck's operation -- keep the gauge's needle within the green zone and you know that you're at the best efficiency for the situation you're in. Quick take-offs and hard acceleration put you out of the zone, a sign that you're wasting fuel. The gauge can be a good fuel-saving device if you pay attention to how your actions affect the truck's power needs, and then break gas guzzling habits.
Variable Automatic Transmission
Silverado and Sierra hybrid trucks are equipped with a constantly variable transmission (GM calls it electrically variable), meaning there are no specific gear ratios. A computer senses the driving conditions and adjusts the transmission to the best ratio -- eliminating the typical jerking motion you feel when a transmission shifts up and down trying to find the right gear.The transmission does have a manual mode (tap up/tap down control) that's handy if you need to downshift for any reason -- say to travel down steep grades or to control the truck's speed in slippery conditions. When manual mode is engaged the computer allows you to shift between four pre-determined gear ratios that are similar to those found in a conventional automatic.
I was fortunate to have Mark Cieslak, Vehicle Chief Engineer, in the passenger seat during my hybrid truck road tests. He said they had originally incorporated a tow mode into the transmission, but eliminated it after road tests indicated it wasn't needed.
The combination of engine, electric motor and transmission operation make the trucks feel and sound "different," not bad -- just different. It's a variation I think most of us would quickly get accustomed to.
Regenerative Brake System
GM's hybrid trucks have a regenerative brake system -- every time you apply the brakes (or coast) it helps charge the hybrid battery.I talked to Mark about the new brake system, asking how it had impacted brake pad life and the truck's stopping abilities. He said the hybrids' brakes perform better overall than conventional brakes, with a shorter stopping distance and longer pad wear.
Hybrid Truck Towing Abilities
We parked the Silverado and got into a Sierra hybrid with a 6,000 pound boat and trailer on the back. Could I tell a difference in the truck's power when it was pulling a heavy load? Sure, but the difference was what I'd expect from any half-ton pickup truck under the same conditions.As you'd expect, pulling a trailer required more use of the truck's V8 mode.
- Towing Specs:
- 2WD Crew Cab: 6,100 pounds
- 4WD Crew Cab: 5,900 pounds
GM Hybrid Fuel Economy
- 2WD Crew Cab: 21 city / 22 highway
- 4WD Crew Cab: 20 city / 20 highway
Hybrid Truck Wrap Up
Mark mentioned to me that GM had performed extensive driving tests in all sorts of conditions, from the high mountains to the desert, to make sure they were durable and reliable. I'm anxious to spend more time in both trucks, but my first impression tells me they got the job done.Overall, the Sierra and Silverado hybrids don't sacrifice any of the things you'd find in the 1500 version of either truck.
Both of GM's hybrid trucks should be in production sometime during the first half of 2009. Prices will be announced in late 2008.
Quick Facts About GM's Hybrid Trucks
