Automated Manual Transmissions can improve fuel efficiency by up to 22 percent over conventional automatic transmissions
, according to a study conducted by Roush Industries for the U.S. Army Tank Automotive Research, Development and Engineering Center/National Automotive Center.

Eaton Corporation, the industrial manufacturer, revealed the results of the study in a release Thursday. The company provided Roush with the gear ratios and estimated efficiencies for a series of newly designed UltraShift Plus heavy-duty automated transmissions for vocational and severe-service use, according to Jeff Spitzner, military account manager for Eaton's Vehicle Group. They will be released for limited production this fall.

"In order to eliminate uncontrollable outside variables and provide repeatable results quickly, the test was conducted using analytical simulation software that factored in optimized final drive ratios," said Spitzner. "That was able to provide a realistic comparison, and to take advantage of the wider operating ranges that are available on Eaton AMTs. The test went on to conclude that the fuel economy gains may be attributed to the greater efficiency of AMTs. In addition, the increased number of gears that are available, complimented with an optimized shift schedule, will keep the engine running in its most efficient range."

"We are extremely pleased with the results of this study as it once again confirms the fuel-saving benefits that are inherent in our growing lineup of automated transmissions," said Staci Kroon, senior vice president and general manager, commercial vehicles for Eaton's Truck North America division.

For more information, visit www.eaton.com or www.roushind.com.