Truck fuel costs are embedded in almost everything you buyEven if you've never driven a single mile in your entire life, a lot of what you own and what you eat has spent hundreds of miles inside a truck. While we can minimize that by consuming less, eating more local food, and shipping more freight via more fuel-efficient trains, but most store shelves will still be stocked with goods that rode in trucks, so making them more energy efficient and cleaner matters a lot. It matters to the environment - because of CO2 and smog-forming emissions - but also to your wallet. You are the one paying for all these trucks because their costs are embedded in the costs of the goods they carry.
A modern long-haul truck typically gets between 5.5 and 6.5 MPG. Cummins and Peterbilt Motors have partnered to create the 'SuperTruck' pictured above, and they've been able to get fuel economy to 9.9 MPG under real world testing conditions (that matters -- theory and practice can often diverge a lot), an improvement of ±54% that would "save about $25,000 annually based on today’s diesel fuel prices for a long-haul truck traveling 120,000 miles per year." The freight efficiency improvements are even better:
In addition to the fuel economy improvements, the truck also demonstrated a 61 percent improvement in freight efficiency during testing compared to a baseline truck driving the same route. That significantly exceeded the 50 percent SuperTruck program goal set by the U.S. Department of Energy. Freight efficiency is an important metric in the transportation industry that is based on payload weight and fuel efficiency expressed in ton-miles per gallon. (source)
This was achieved without anything too exotic: The 'SuperTruck' uses a higher-efficiency engine and an aerodynamic tractor-trailer that significantly reduces drag combined with a waste heat recovery system, electronic controls that use route information to optimize fuel use, low-rolling resistance tires, and weight reductions all around.
And because most of the improvements made are not diesel-specific, a compressed natural gas (CNG) or liquefied natural gas (LNG) version of the 'SuperTruck' (or other equivalents by other companies) would be possible. It probably wouldn't save that much carbon, but smog-forming emissions would likely be much lower.
'SuperTruck' is one of several initiatives under the 21st Century Truck Partnership, which is a public-private partnership founded to further stimulate innovation in the trucking industry through the sponsoring government agencies, companies, national laboratories and universities. Testing will continue in 2013, and the partners feel confident they can keep improving the 'SuperTruck'.