From the outside, this pickup looks like any other Silverado Crew Cab, and you'd never guess that it got better fuel economy around town than a Scion tC coupe or a Volkswagen Jetta. Yup, this truck in two-wheel-drive trim gets 21 mpg city and 22 mpg highway. Plus, it can still haul (1,400 lbs) and tow over three tons. The Hybrid version comes as a Crew Cab only with two- or four-wheel drive. There are two trim levels, with the cloth-interior version starting out at about $39,000. A premium model is also available, and it offers more features including leather seats for about $48 large. Frankly, if it didn't have Hybrid stickers on it (a no-cost option), you'd never know that this truck was packing more high technology than the Apollo missions to the moon.
Hybrid Tech Talk
So what's so high-tech about this truck? How about electric power steering? Instead of being run by a belt off of the crankshaft, the rack-and-pinion steering gets its boost from a 42-volt electric motor. Likewise, the air conditioning compressor is no longer belt-driven but spun by a separate, variable-speed 300-volt motor. Yup, this pickup packs a battery pack capable of flowing 300 volts. That's enough to get your attention if you mistakenly cut the main cable!
Even more important than the electrically-driven accessories is the hybrid system's main component, GM's EVT (Electrically Variable Transmission). General Motors, Mercedes-Benz (when it owned Chrysler), and BMW co-developed the EVT. Within a case that looks like a traditional automatic gearbox, GM managed to package two motor/generators and four fixed gear ratios. The EVT attaches to the engine just like a regular automatic, but nothing inside the EVT works like a regular slush box. The engine's output shaft runs into the EVT where the torque is electronically routed out the tail shaft in the most efficient manner. Computers running sophisticated algorithms pick the gears and specific settings for the motor/generators that are at the fore and aft of the gearbox.
Each motor/generator can produce 81 horsepower and 184 lb-ft. This is enough power to run the Silverado on electricity only from a stop up to nearly 30 mph. The extra torque from the motors also adds power when the driver floors the throttle. Four fixed gear ratios are physically sandwiched between the two motor/generators. These motor/generators are planetary gearsets, so the gearbox is capable of an infinite range of gear ratios (like a continuously variable transmission). While regular CVTs are great for optimizing fuel economy, they don't handle heavy loads very well. GM's version of the CVT does. This is where the fixed gears within the Silverado's EVT come into play. When towing, for example, the planetary gearsets lock to let the heavy-duty fixed gears handle the load.
When the EVT isn't sending power to the rear axle (or to the two-speed transfer case in four-wheel-drive models), it's producing its own power (electricity). Here's how it works: if the Silverado is coasting or slowing due to light to moderate pressure on the brake pedal, the Chevy's disc brakes aren't actually slowing the truck. The EVT is. The dual motors in the transmission instantly switch to become generators, and as the truck's propshaft transfers the truck's kinetic energy into the transmission, the generators spin up to produce electricity. The electricity charges the truck's 300-volt nickel-metal hydride battery pack for later use.
In addition to the battery pack (which resides under the rear bench seat), ahead of the EVT is where you'll find the third piece that makes the Silverado Hybrid unique; the advanced V-8 engine. The mill is an all-aluminum 6.0-liter that utilizes cylinder deactivation (so it can run in V-4 mode) and variable valve timing (that enables the late closing of the intake valves to reduce pumping losses) to improve fuel economy. The 6.0-liter produces 332 horsepower and 367 lb-ft of torque.