GM announced plans Tuesday to roll out a second-generation version of the GM Hybrid System with a more powerful lithium-ion battery. The announcement comes just weeks after GM vice chairman Robert Lutz called global warming a "total crock of s***."

The new system, powered by a Hitachi-supplied advanced lithium-ion battery, is expected to be nearly three times more powerful than the system it replaces. Overall fuel economy improvements for cars and trucks using the system are expected to rise up to 20%, depending on engine and vehicle application.

The crock quote came from Dallas Magazine's Frontburner blog. But Lutz isn't down on the planet; he's down on imported oil. "I'm a skeptic, not a denier. Having said that, my opinion doesn't matter. I'm motivated more by the desire to replace imported oil than by the CO₂" argument.

On his own blog, Lutz asserts that both he and GM are "dedicated to the removal of cars and trucks from the environmental equation, period."

GM's road map backs that up. The next-gen hybrid system is designed to complement GM's Two-Mode Hybrid system, which will be offered this year in the Cadillac Escalade full-size SUV. That's the car Super Bowl MVP Eli Manning is waiting to drive home this summer, as part of his Bowl-winning prize loot. By the end of 2008, GM says it will offer eight hybrid models in North America.

Under Lutz's direction, GM also is working to push the plug-in hybrid Chevy Volt into production by 2010.

How advanced is the Volt's technology? Let me put it this way: How many other cars do you know that have their own CTO?

To really understand the technology behind the electric hybrid, read Popular Mechanics' Inside Plug-in Car Tech's Race to Production.