Parallel Hybrid Truck Engines

[TxDoc]

Found this on GM.media.com:

 

Parallel Hybrid Trucks

 

"powertrain is derived from GM’s innovative Parallel Hybrid Truck, which brings together a 285hp, 5.3-liter VORTEC V8 gasoline engine and a powerful electric motor/generator"

 

A 4.8-kilowatt motor/generator is integrated into the drivetrain between the gasoline engine and the transmission. This provides starting power and the ability to generate electricity during deceleration. It also saves weight and parts because a conventional starter and alternator are no longer needed.

 

"At a stoplight, the gasoline engine shuts off, but the accessories continue working on stored electrical power. When the light turns green and the driver depresses the accelerator, the gasoline engine restarts automatically. The truck gets more miles per gallon because of the stop/start function, torque-smoothing for improved powertrain efficiency, and regenerative braking, which turns the motor into a generator to capture energy as the truck decelerates.

 

The parallel hybrid system offers fuel savings of up to 15 percent with no reduction in the truck’s towing capacity. This system will be available as a powertrain option on GM’s full-sized pickups, the GMC Sierra and the Chevrolet Silverado, beginning in 2004."

[Shumdit]

GM has been talking this and even showed a few of the car magazines working prototypes. The trucks will be the first to have the 42 Volt electrical system to make it possible. For the first generation you will see multiple voltage, that is 42 volts for the drivetrain and 12 volts for all accessories, but eventually all electrical will go to 42 volts. This will allow engines without camshafts (electric solenoid valve actuation), which will further improve fuel economy, as well as offer variable valve timing. The main drawback to this system may be added cost. GM has a cylinder deactivation valve that will go into production for 04 that will seamlessly switch to 4 cylinder mode under light throttle (cruising) conditions. This is also expected to improve fuel economy from 10-20 % (depending on your driving habits/conditions) and will only add about $175 to the cost of the truck. In testing journalists said they could not tell when then engine switched modes, so this looks very promising. I think they stated 25-30 % improvements with both technologies, but that was about 2 years ago, so that figure may be incorrect. It looks like it will be interesting to watch the developments.

[Guest Friz]

It is interesting and sounds promising from a fuel economy and reduced emission point of view.

I am still very leery of the cylinder deactivation and the stop/start motor features.

I'm and old gearhead that just recently began to embrace computer controlled fuel and electronic ignition. It just seems to get harder and harder for us grease monkeys to modify our trucks.