Quick Facts: Fuel economy in city driving improves by more than 50 percent. Escalade can run briefly on batteries alone, or the gas engine. V-8 engine deactivates half of the cylinders when power demand is low.

Big can be green. At least, that's the thinking behind the 2009 Cadillac Escalade Hybrid.

The big SUV uses General Motors' 2-Mode Hybrid system, which allows the truck to be moved by just the battery power at low speeds, or by the gasoline engine at higher speeds. Transitioning from one to the other is seamless.

To make the truck even more fuel-efficient, the engine automatically deactivates four of the eight cylinders when cruising or when power demand is relatively low.

All of these features combine to improve city driving fuel economy by more than 50 percent.

Look for the big hybrid at your Cadillac dealers starting in the summer of 2008.