Chevy Trucks, Chevrolet Trucks

Chevrolet unveiled its new hybrid chevrolet Silverado truck at the 2007 Los Angeles Auto Show, and showed us the Sierra hybrid a few months later. Let’s take a quick look at both hybrid trucks before we get into the specifics:

* GM’s hybrid trucks will be available as Crew Cabs; choose either 2WD or 4WD

* Look for a 40-percent gain in city fuel economy and a 25-percent gain overall (when compared to a conventional Silverado or Sierra); cruising range is more than 500 miles

* The trucks are equipped with GM’s 2-Mode Hybrid system

* Both trucks have a 6-liter V-8 engine with Active Fuel Management and late-intake valve closing technology

* Capable of all-electric drive up to 30 miles per hour

* Towing capacity of 6,100 pounds for the 2WD truck

* The only (as of November, 2007) full-size hybrid pickup truck; goes on sale in late 2008 as a 2009 model (update: first half of 2009)

Hybrid Truck Drivetrain
The trucks are equipped with GM’s 2-Mode Hybrid System:

An electronic variable transmission (EVT) allows infinitely variable gearing when it’s advantageous for a truck’s efficiency, but automatically changes modes to act as a conventional transmission (with four fixed gear ratios) when necessary, typically when you’re driving at higher speeds or have increased hauling needs.

The trucks’ Hybrid Optimizing System (HOS) constantly sends information to the EVT, optimizing transmission operations for best performance and economy.

The Energy storage system (ESS) is a 300-volt battery that’s located in the chassis, underneath a truck’s rear seats. It provides power to the EVT and stores the energy it captures during deceleration, when braking, and when the system converts one of the truck’s two electric motors into a generator.

The ESS powers the A/C compressor and the Accessory Power Module (APM), which in turn feeds the truck’s 42-volt power steering system, its 12 volt battery and other 12-volt systems.

The big battery is cooled by a system that draws air from within the passenger compartment. It has an 8-year / 100,00 mile warranty, and GM says the ESS has safety features to keep it from over-charging, over-heating, being penetrated by liquids, and from accidental access to its components.

The 6.0L V-8 engine runs on regular gas and the engine is equipped with an Active Fuel Management (AFM) system. A computer controlled late-intake valve closing (LIVC) feature lets the truck run on 4 or 8 cylinders, whichever offers the best performance and economy for the job.

GM doesn’t have official EPA ratings for the hybrid truck yet, but based on their own tests and the new Tahoe’s ratings, the company expects a 40 percent increase in city fuel economy when compared to a similar conventional Silverado. (update: see ratings in my First Impressions Road Test