Just in time for President Obama’s mandate to slash big truck emissions – and our own story on innovative series hybrid trucks that promise a paradigm shift in truck efficiency – Cummins and Peterbilt announced the 10.7 mpg “SuperTruck.”

Cummins and Peterbilt say tweaks to the big rig are a significant step forward all by themselves, considering a fully loaded, 64,000-pound class 8 truck like this would have been seen as OK if it netted 5.5-6.5 mpg just a few years ago.

Improvements for the SuperTruck include an average 75-percent increase in fuel economy, 43-percent cut to greenhouse gas emissions, and 86-percent increase in freight efficiency. These numbers were said to be “real world” indicators based on 24-hour, head-to-head testing running at 64 mph against a 2009 baseline truck.

Behind the SuperTruck program is the U.S. Department of Energy (DoE) already working ahead of Obama’s latest mandates, and for which the truck was on display as a symbol of progress.

“We are honored that the Cummins-Peterbilt SuperTruck has been chosen to be on display for President Obama’s announcement,” said Wayne Eckerle, Cummins vice president – Research and Technology. “The SuperTruck clearly demonstrates the technologies that can deliver significant fuel-efficiency improvements over the next decade and beyond as we continue to develop for cost and performance attributes that will make them strong commercial successes.”

Gains were attributed to the Peterbilt Model 579 with “best-in-class” aerodynamic efficiency. The Cummins ISX15 engine converts exhaust heat to additional crankshaft-turning power, and the system is controlled electronically to maximize fuel usage. Of course a host of diesel exhaust after treatment is also employed.

Weight was also pared off of the big truck. Its 312-mile test route was the same course that saw just under 10 mpg for the first version of the Peterbilt SuperTruck two years ago.

At today’s diesel prices, Cummins and Peterbilt estimate an annual fuel savings of $27,000 over a 120,000 mile year.

In short, the truck was improved by around 1 mpg after two years of refinement. It represents upticks in several places that had room for improvement, and substantial fuel and emissions savings to be sure, but still represents a traditional diesel big rig.

It contrasts to the plug-in series hybrid tech utilized by San Jose startup Wrightspeed featured today, which also is beginning work on class 8 trucks.

That company, having previously specialized on class 3-6, has seen for medium-duty trucks a 300-percent fuel efficiency improvements and emissions 10-times better than required by the California Air Resources Board.

It does have more to prove being a startup going against the tide, and is far less established than mainstream players.

However, Wrightspeed promises many times greater efficiency, and has done so in only a few years, and with less than $17 million in total investment and grant capital received since the company’s inception.