[mkaresh]

Originally Posted by Michael_S

The 6.0 in the Hybrids was motified to use the Atkinson combustion cycle, which is also used in the combustion engine in the Prius and a few other hybrids.

Otto cycle (normal gas and diesel engines): fuel and air are compressed the same amount they are expanded. If they're compressed 10 to 1, they expand 10 to 1 before exiting through the exhaust valve.
Atkinson cycle: it provides less power but more efficiency, because fuel and air are expanded more than they are compressed. They might be compressed 10 to 1 and expanded 12 to 1, which extracts more energy per unit of fuel.

That's why the 6.0 in the Tahoe and Yukon hybrid only makes 332 horsepower while every other current GM truck or SUV with the 6.0 gets at least 350 horsepower.

Is the 332 for the engine alone, or the engine plus the hybrid motors? Other hybrid sellers have gone both ways. For example, the engine in the Highlander Hybrid is rated at 268 horsepower with the electric motor, and 209 without it.

The 332 seems low enough to be without including the electric motors, but somewhere recently I read that this figure includes the output of the electric motors. Which could be wrong.

Any idea?