The beauty of the hybrid truck

OSHAWA, ONTARIO - Contrary to what you may have heard, General Motors is still building trucks in Oshawa — and at least one of them is rather futuristic.

While most hybrids are small and lightweight, this one is a full-sized, half-ton truck. And, frankly, isn't driving a 2.75-ton vehicle where you'd want the greatest fuel economy?

That's what I figured when I arranged this first test of the 2009 Chevy Silverado Two-Mode hybrid pickup.

What makes this truck a hybrid is GM's Electrically Variable Transmission (EVT) and the 300V nickel-metal hydride Energy Storage System (ESS) that saves and gives back previously untapped power. It does this in two ways (hence the name Two-Mode). From a standstill, the Silverado launches and drives up to 45 kilometres an hour on electricity alone, then the 6.0-litre gas engine takes over.

But this V8 engine also has Active Fuel Management (AFM) and late intake valve closing (LIVC) technology, which lets it operate in V4 mode once it has reached highway speeds. To help it stay in V4 mode as long as possible, the EVT also offers the equivalent of a 30-horsepower boost of electric power when needed at high speeds.

I drove this truck for a total of 1,600 km during the Christmas holidays. My total klicks broke down to about a 60/40 split between highway driving and a mix of city and in-town expressways.

How did I drive it? Well, I hauled a couch, delivered an ATV, took Christmas gifts to Grandma's, fought for parking at the mall and ferried four turkey-stuffed family members around — in a breath, normal stuff.

The beauty of this hybrid is that, while it's great to understand how it works, you don't have to. Inside, the only indication that you are even driving a hybrid is the tachometer with an Auto Stop indicator on it (this signals when the gas engine is shut down, though all functions such as the heater remain on).

During the first 10 days of my test (mostly city driving), I averaged 12.6 L/100 km. This, of course, is the result of the engine frequently shutting off at stoplights and while idling. Also in stop-and-go traffic, the electric motors propelled the truck exclusively.

After New Years, I ran my son back to university in Ottawa. I set the cruise at 120 km/h and did the 503 km on 75 litres of regular fuel — or 14.9 L/100 km. The return trip data was almost identical.

It has to be noted that both these results are less than the Canadian EnerGuide quotes for this GM hybrid — but then I've never had a test vehicle that duplicated those government numbers anyway. Still, I'll quote its fuel consumption numbers as a non-partisan way of comparing the performance of the hybrid vs. non-hybrid truck. According to the guide, the highway consumption difference is 1.9 L/100 km less while the city figure is 6.1 L/100 km less.

As for the truck itself, the hybrid system uses the GMT900 truck (all new in 2007) as its host. Specifically, one model is currently available, a crew cab shortbox model. Mine was the four-wheel-drive version with a curb weight of 2,667 kg. From the outside, the only thing that sets it apart from a normal Silverado is a hybrid badge and some stenciling.

That's it, really; no other major body changes were necessary because the hybrid electric motors are neatly fitted into the EVT transmission housing (this makes it easy to mate to other vehicles such as the Tahoe and Escalade, which has already been done) while the battery array is sealed in a box under the rear seat. With a warranty of eight years/160,000 km on the ESS, little or no thought need ever be given to the hybrid function at all.

An issue with some other hybrids on the market is towing. Specifically, they can't. Not so with the GM system. This tranny will handle up to 2,676 kg. Earlier this year, I set up a towing test with the identical hybrid system in an early-build Chevy Tahoe. My choice of trailer (2008 Keystone Sprinter with a length of 28 feet, 11 inches and a weight of 2,866kg) pushed the Tahoe to just past the limit set by GM.

I noted that from a standing start the electric motors alone moved the trailer easily and at higher speeds (sticking to the speed limits) and the V4 would still stay engaged on level pavement at 80 km/h. I also ran the unit in cruise control and the truck maintained its speed all up and down through the hilly Oak Ridge's Moraine countryside. Still, if I floored the pedal, the truck responded instantly — easily pulling the trailer into the traffic stream. For this test, I averaged 19.7 L/100 km.

So, what's the cost of economy or being green? About $10,000 more than a non-hybrid truck. You can narrow that gap somewhat if you go with the 2WD version, which knocks $4,150 off my 4WD tester's price.



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