9 July 2008

A review by the National Research Council has found that the “21st Century Truck Partnership” (21CTP) R&D program—a joint US industry/government effort to increase fuel economy and reduce emissions in heavy-duty vehicles, started in 2000—has a number of flaws in its goals and results. The review was requested by the director of the Department’s of Energy (DOE) Office of FreedomCAR and Vehicle Technologies.

Some key 21CTP program goals were not met because they were not plausible—from either the engineering or funding perspective—or the technologies necessary for meeting them were not applied, determined the review. However, the 21CTP has also had a number of successful programs, found the review committee, and should be continued but in a revised and better balanced form to match current funding and technology levels.

Most of the issues were identified in the engine systems and fuels part of the program, which aimed at achieving 50% thermal engine efficiency by 2010 and 55% by 2013, and was to identify fuel formulations that could replace 5% of petroleum fuels by 2010.

Although the DOE concluded that the 50% thermal efficiency goal has been achieved, the results show that none of the industry partners (Cummins, Caterpillar and Detroit Diesel) achieved the 50% goal with engine conditions representative of typical 65 mph full-load highway driving. Under such a 65 mph operating condition, the real efficiency would fall to about 46.6%, not 50%, calculated the review.

The DOE failed to clearly specify the engine efficiency goal, according to the review committee, and each of the industry partners used different test procedures for measuring thermal efficiency, and did not use the EPA test protocols with aged engine/aftertreatment system to demonstrate 2010 emission compliance.

The review committee was also critical about the 21CTP low temperature combustion (LTC) research, which focused on various variants of homogenous charge compression ignition (HCCI) combustion. The technology does not look promising for increasing engine efficiency while reducing criteria emissions, according to the review. If feasible, LTC engines would have to be able to use today’s commercial diesel fuel, noted the review.

The review also analyzed the 21CTP results in several other areas, including hybrid vehicles, parasitic loss reduction, and engine idle reduction.

Source: National Academy of Sciences