Consider this: The average semi truck is actually quite economical.

No, really. A typical long-haul truck averages between 5.5 and 6.5 mpg. But it's also really, really heavy--up to 80,000 pounds, for a fully-loaded trailer. That's around 36 tons, which puts some perspective on how hard each of those gallons are working. When some pickup trucks manage barely double that with significantly less weight, long-haul trucks really are impressive.

Not that there isn't room for improvement--such as the new 9.9 mpg Peterbilt and Cummins 'SuperTruck'.

It represents a 54 percent improvement over the typical semi, as conducted over 11 runs of SAE-rated testing last fall. In 312 miles of testing, the SuperTruck returned the near-10 mpg figure with a gross weight of 65,000 pounds.

Some of the other statistics associated with the truck's efficiency are even more eye-opening.

Consider, for example, the fuel savings of a truck that achieves 54 percent better than usual economy. Over 120,000 miles per year, the average truck would use $25,000 less diesel. It would also result in a 35 percent reduction in greenhouse gases per truck.

That comfortably exceeds the proposed 10-20 percent improvement suggested by the EPA back in 2010.

With 2 million registered tractor-trailers on U.S. roads today, the fuel savings and reduction in pollution could be staggering. For freight operators, the 61 percent improvement in freight efficiency--a measure of payload weight and fuel efficiency--is also useful.

So what separates a SuperTruck from your average truck?

Perhaps unsurprisingly, many of the same techniques used to improve the fuel efficiency in regular automobiles--low rolling resistance tires, lightweight materials and a higher-efficiency engine.

The tractor and trailer units themselves have also been designed to improve aerodynamic efficiency--most noticeable in the tractor unit's covered rear wheels. The truck also uses a system to convert exhaust heat into power delivered to the crankshaft, electronic controls that use route information to optimize fuel use, and a reduction in parasitic losses from pumps and compressors.

Cummins, Peterbilt and other investors have put $38.8 million into the project, with matching grants from the Department of Energy's Vehicle Technologies Program.

When improvements are as great as those seen in the SuperTruck, it actually makes such investments seem entirely worthwhile, saving haulage companies millions from year zero--not always the case with some automobile projects.

As testing of the SuperTruck continues, both companies feel they can improve the truck further--just how efficient can you make a dozens-of-tons truck?


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