The current range of 21st century warming, according to the Intergovernmental Panel on Climate Change, is 3-8 F.

CNN: Clouds' role in global warming studied

The new optional engine on Silverado and Sierra also beats out the 15 mpg in the city and 21 mpg on the highway yielded by the 5.0L V-8 engine in two-wheel-drive versions of the F-150 and the 14 mpg in the city and 20 on the highway provided by a 4.7L V-8 engine in two-wheel drive versions of Ram.

FORBES: GM Scores EcoBoost Via Higher MPG Claim On New Silverado

Consumers have already responded to the Administration's fuel efficiency standards for Model Years 2011 through 2016, and it shows in the popularity of cars like GM's Chevy Cruze and trucks like the Ford F-150 equipped with an EcoBoost engine instead of the conventional V-8.

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Kerkorian's Tracinda reported that it again increased its stake in Ford Motor (nyse: F - news - people ) to 6.5%, or 140.8 million shares, from 5.5%.

FORBES: Kerkorian Standing Stronger Behind Ford

For the Ford F-150, the most popular vehicle on American roads, they take out the inevitable V-8, and replace it with a four-cylinder engine, an average of 22-kilowatt-hour battery packs, and two 60-kilowatt electric motors.

FORBES: Written by Jim Motavalli