Photos Copyright ©2009 Jeremy Korzeniewski / Weblogs, Inc.
These two workhorses were first announced at the LA Auto Show
in late 2007, though the 2009 editions are just now beginning to show up at dealerships
across the country. For the new model year, GM has made a few tweaks to its range of heavy haulers, most notably switching to a new set of hydraulic body mounts to compensate for the extra weight of the large battery pack. Are there any good reasons to consider these hybrid trucks
over their highly-respected standard siblings? To find out, we strapped ourselves behind the wheel of each, followed a route through the streets of San Antonio, Texas, and recorded our mileage along the way.
While working hard to maximize fuel efficiency
, we also paid close attention to how these two pickups responded to our commands to accelerate, brake and turn. Why? There's a ton of technology that goes into making these hybrid trucks tick, including a sophisticated automatic transmission that features four fixed forward gears along with twin planetary gearsets allowing continually variable ratios for the dual electric motors -- each offering 60 kilowatts of power to assist the engine. Suffice it to say, there's a lot going on when your foot presses the accelerator.
Electricity is stored in a 300-volt nickel metal hydride battery pack located under the rear bench seat. It's probably safe to assume that future versions will move to lithium ion packs once the price goes down and production ramps up. The huge bank of batteries also provides power to a 300-volt air conditioning
compressor that allows the cabin to stay nice and cool even when the engine isn't running. GM understands there will be concerns about the life expectancy of the expensive battery pack, so the warranty
on hybrid components is boosted to eight years or 100,000 miles, whichever comes first. The rest of the truck is covered under the same five-year warranty that non-hybrid trucks carry.
The majority of the power comes from a 6.0-liter V8 equipped with cylinder deactivation technology, allowing the big mill to act as a V4 when all eight pistons aren't required for propulsion. Auto Stop is also included, preventing the engine from needlessly idling when sitting still. Add it all up, and GM's 2-Mode hybrid powertrain has three sources vying for the right to move you forward, and as you may imagine, there's enough processing power from the five CPUs to run a NASA-sponsored trip to the moon. The computers track everything from the current state of the battery's charge to how much pressure is being exerted on the gas pedal, all of which ensures the truck will stay smooth and refined when navigating the tight confines of city traffic or running down the expressway.
In practice, there are a few tell-tale signs that this isn't a conventional truck. Keep an eye on the Eco Gauge at the far left of the dash and you'll be reminded to tread lightly. A feather foot on the go pedal will get the ball rolling without starting up the engine, and at speeds of up to 30 mph, the truck is capable of traveling without a single drop of gas -- a feat we were able to replicate several times on our trip. Eventually, the internal combustion engine will kick-in, providing a slight but noticeable change in sound from the tech-rich drivetrain. The engine's engagement is based on a host of factors, including the incline of the road, the driver's use of the throttle and how much weight is being carried. When slowing down, a very faint shudder can occasionally be felt as the V8 engine switches off, but it's hardly as jarring as earlier systems.
The electric power steering felt surprisingly normal, with just the right weighting for a vehicle carrying this much mass. We also took the time to drive a Sierra Hybrid with 850 pounds in the bed, and, as expected, the extra weight helped smooth out what was already a nicely tuned and comfortable ride. A quick spin
on another short loop proved that the electrically-assisted pickup was rather adept when it comes time to hook up a trailer, which we tested with 5,300-pounds of dead weight. Even with such a large load, a very light press of the accelerator would get the truck rolling solely on electricity. The maximum tow rating currently sits at 6,100 pounds for the rear-wheel-drive models and 5,900 for four-wheel-drive versions, but GM's brain-trust believes they can improve that number significantly.
So, the driving portion of our test proved that the hybrid trucks worked exactly as expected. The big question, though, is how much fuel do they save? The EPA
rates the duo at 21 mpg
in the city and 22 on the highway in rear-wheel-drive trim and 20 city, 20 highway in four-wheel-drive guise. We managed a mark of 21.5 mpg in the RWD model during city testing with three occupants and the climate control set at 68-degrees. By way of comparison, the fuel-saving, non-hybrid XFE model gets an EPA rating of 15 city, 21 highway and it's not available with 4WD. As with most hybrid systems, the big savings comes when driving in the stop-and-go traffic common in the city, with the hybrid powertrain accounting for a 40% improvement in fuel mileage. On the superslab, the 2-Mode technology is a bit less effective, even with a revised front fascia, lower air dam and rear tonneau cover eking out a single extra mile per gallon in highway testing.
Since the efficiency improvements are so heavily weighted in favor of city driving, GM expects that its hybrid trucks will appeal mostly to fleet operators that do the majority of their driving in urban centers. But the biggest barrier to potential ownership will be the price. The starting MSRP for a well-equipped base model is $38,995, and we noticed sticker prices for versions fitted with leather seating surfaces, a sunroof and navigation systems creeping over $45K. Even after subtracting the federal tax
credit of $2,200, it's clear that owners will need to drive plenty of miles before the fuel savings start to pay off. Even assuming that gas increases to $3 a gallon and that almost all of your driving will be done in the city, it will still take several years before the hybrid truck's running costs equal those of the XFE edition -- at least on paper. However, there are several items that the hybrids are equipped with that cost extra on lesser models, so we'd suggest that you do your own calculations if the sticker price is your biggest concern. For those who want to use as little gas as possible but still need the capabilities of a full-size pickup truck, the hybrid twins from General Motors
will fit the bill nicely. So let the love affair continue.