This week at the Chicago Auto Show, GMC unveiled two vehicles that point to a more fuel-efficient future for trucks: The 2009 Sierra Hybrid and the Denali XT concept vehicle.

The Sierra Hybrid represents the first look at a new production model that goes on sale later this year, while the Denali XT – also a hybrid – supposes a new, more efficient direction in truck design. Both are indicative of GMC and General Motors’ commitment to improving fuel economy and reducing the reliance on petroleum.

GM’s patented two-mode hybrid system (the same in the Yukon Hybrid that is already in production) is the motivating force in the Sierra Hybrid, giving it a 25-percent improvement in overall fuel economy. As impressive as that sounds, it is city driving where it really shines. With all-electric drive up to about 30 mph, the Sierra Hybrid can deliver up to 40 percent improved fuel economy in city driving.

And, no, the truck doesn’t sacrifice capability for mpg. It has a payload rating of more than 1,400 pounds and a towing rating of 6,100 pounds. That’s a fuel-efficient reality that will be in the showrooms later this year.