For example, a new air dam below the 2014 Sierra’s front bumper successfully reduces drag because it directs air toward the ground and away from the truck’s rough underbody. And Sierra’s ducted flow path between the grille and radiator prevents air from swirling inside the truck’s front cavities.

Even the top of the Sierra’s tailgate and the center high-mounted stop light are optimized to guide air cleanly around the truck. And because Bloch’s team detected unwanted airflow between the cab and bed, new sealing has been added.

“We discovered that in the computational analysis we perform,” said Bloch. “The most harmful air between the cab and bed was coming over the cab and down through the gap, so we paid the most attention to that specific area.”

I seem to remember that pick-up trucks just perform poorly when it comes to CAFE regulations. I figured that they bring down the average for the company's line-up. Perhaps I am wrong, but even so, trucks aren't the best when it comes to MPG and companies must have an interest in getting those figures down.

Trucks themselves are just horrible in that department than anything else from the start, just due to the nature of its weight and size

They also all seem so boxy at the front. I'm sure they could come up with a more aerodynamic design, but perhaps that wouldn't be as good for capabilities. It seems like a truck that has great MPG numbers would sell well since it would stand out from all the rest.

For the past few years, a quirk in federal policy has made it easy for Americans to keep supersizing their rides: Under CAFE rules that took effect in 2011, bigger cars have lower mileage requirements. For the first 30 or so years CAFE was on the books, the rules divided the market into cars and light trucks but held all vehicles in each class to the same fuel-efficiency standard. Automakers that sold only gas guzzlers, whether big cars or big trucks, had to pay penalties. That changed with a reconception of CAFE that began under President George W. Bush in 2008 and culminated in rules the Obama administration promulgated for 2011 and beyond.

Trucks themselves are just horrible in that department than anything else from the start, just due to the nature of its weight and size

I seem to remember that pick-up trucks just perform poorly when it comes to CAFE regulations. I figured that they bring down the average for the company's line-up. Perhaps I am wrong, but even so, trucks aren't the best when it comes to MPG and companies must have an interest in getting those figures down.

American companies do just as well as their competition, they have to, to stay competitive of course.

Just because a brand makes pickup trucks doesn't mean they don't do as well with CAFE regulations. Where did you get that from? If what you're saying is true that means Toyota and Nissan don't do as well with CAFE regulations than other japanese brands because they make pickup trucks