The folks at General Motors recently showed up in town to tout the two-mode hybrid system, which debuts in the 2008 GMC Yukon and Chevrolet Tahoe full-size SUVs (both equipped with 6.0-liter V-8 engines).
The all-new electrically variable transmission employs two 60kW electric motors and a 300-volt nickel-metal hydride battery pack. The battery pack essentially provides power to the two motors. These work in concert with GM's Active Fuel Management system, which deactivates four of the eight cylinders, especially while cruising on the highway.
Unlike in the non-hybrid vehicles, the hybrid system ensures the longevity and frequency of the engine in V-4 mode for maximum fuel economy.
In the first mode, which is for low speed or light load, the vehicle works in electric power, gasoline engine or a combination of both. The second mode is for highway speed and provides electric assist as well as four- or eight-cylinder power.
During stops or slowdown, the battery gets recharged so it has plenty of juice for immediate use.
The driver can view the power flow of the hybrid drivetrain on a 6.5-inch LCD screen. An analog "economy" gauge at the top left corner of the instrument panel serves as a guide for the most efficient use of the hybrid system. An "auto stop" sign lights up on the tachometer when the gas engine shuts down at a stop to ensure fuel savings.
The two-wheel-drive version of the hybrid Yukon and Tahoe ekes out 21 mpg in the city and 22 mpg on the highway, which is 50 percent more than the mileage earned by their gasoline-equipped twins.
In summer, the Cadillac Escalade two-mode hybrid should begin production. GMC Sierra and Silverado two-mode hybrid pickups will kick off production and sales in the late fall. The first application of a front-wheel-drive, two-mode hybrid system in the Saturn Vue will start late in the year, arriving in dealer showrooms early next year.
The two-wheel-drive Yukon hybrid starts at $50,945 while the Tahoe hybrid is base-priced at $50,490.
For information on the two-mode hybrid vehicles from GM, visit www.gm.com.