[Previous]  
tried out the Silverado Hybrid with a 5,000-pound, 22-foot Sea Ray
boat and double-axle trailer hanging off its back end. The first 30
seconds driving the Silverado were the most incredible of the hour
we had it. We thought the truck might sense the boat's additional weight
and start with the gas engine engaged to prevent damage to the hybrid
powertrain, but it pulled away with only the golf-cart-like hum of
its electric motors, then stayed in full electric mode until almost
15 mph! There was no strain as it did this, just plenty of torque and
power. The performance was diesel-like. We barely felt the V-8 kick
in as the tach jumped out of auto-stop mode and started registering
the gas engine's RPMs.
is to think how much fuel we saved just getting the combined 11,000-pound
mass of the truck and trailer rolling from a dead stop. This is what
makes the Silverado Hybrid such a fuel-efficient vehicle in city driving,
loaded or not.
the freeway was worry-free and fast – even with the truck's
stout 3.08 rear axle. We had no issue merging with traffic, which was
flowing by at 65 to 70 mph. Again, performance was on par with a diesel
truck, not gasoline. Electric motor noise intruded into the cabin as
we accelerated onto the highway, but it was audibly less intense than
some turbos we’ve heard compressing air in heavy-duty oil burners.
Unlike most diesel pickups, there was no turbo lag. Torque was immediately
[hybrid] system has the torque delivery of a diesel," said Mark
Cieslak, GM's chief engineer for full-size hybrid trucks. "It's
always there for you. That's how it feels. It pulls like a mule. The
other part of it is you don't get the
cadenced shifts like a diesel [when climbing hills]. It's glass-smooth.
The transmission always finds the optimal ratio for you without hunting."
extra aerodynamic drag from the boat, the 6.0-liter V-8 stayed in eight-cylinder
mode at speeds above 60 mph. This leads us to believe that when GM's
half-ton 4.5-liter V-8 diesels arrive next year, they'll probably
prove to be more efficient for frequent medium- and long-distance towing
applications than the Silverado Hybrid.
negative, compared to conventional diesel-powered and gas pickups,
is the Silverado Hybrid's
lowly 6,100-pound maximum tow rating. Heavy-duty pickups can tow two
to three times that much, and the 6.0-liter V-8 Silverado half-ton with
a six-speed automatic transmission can pull up to 10,700 pounds. Part
of the limitation is due to the hybrid's
tall 3.08 rear axle, but it's mostly thanks to cooling requirements
for the truck's sophisticated electronics. The heavier the trailer,
the greater the heat load.
the Silverado Hybrid and future Silverado diesel half-ton to be similarly
priced, so it will be critical to think about how and in what environment
you’ll use the truck before purchasing
Unlike GM’s conventional diesel and gas pickups, the Silverado
Hybrid doesn’t have explicit tow/haul mode gear-swapping logic
to hold RPMs during acceleration or to help grade-brake during long mountain
the electronically variable transmission, you have [the equivalent
of] tow/haul mode," Cieslak said. "It gives
you optimal gearing all the time. Grade-braking is the same deal. [The
EVT] gives you the benefit of the [automatic] braking that you need.
We cadence the hybrid transmission, so if you tap the brake it behaves
just like tow/haul mode."
is also unconventional. The gas engine doesn't drive the
truck backward, but its electric motors spin backward to move the truck
Hybrid has three brake systems that work together to slow the truck:
standard four-wheel disc brakes, the electric motors in the transmission,
and two-stage hydraulic regenerative brakes that use the electric motors
to capture and store brake energy in the truck's
batteries while reducing forward momentum. The calibration between the
brake systems was perfect — incredibly smooth and imperceptible as they
handed off speed-scrubbing responsibilities.
What We're Thinking
Silverado Hybrid's operating range, GM has created what we think is
the smoothest-operating, most-efficient half-ton pickup available today,
though it will take a longer drive to see if its durability is up to
its hype. We recently drove a two-mode Chevrolet Tahoe Hybrid that
suffered a software glitch that took the braking and stability control
systems offline and forced us to swap out for another vehicle. Not good,
but from what we understand, GM found and fixed that unique condition.
the Silverado Hybrid launch happens without further delay or glitches
— and the price is right — hard-working owners are certain to be
pleased with the truck they've bought. They can also grin as they pass
LS 600h drivers, knowing their two-mode "Cowboy Cadillac" is
more efficient than the higher-profile Lexus hybrid.