The manufacturers that supply diesel engines to the motorcoach industry have officially begun the process of getting their 2010 engines certified by the U.S. Environmental Protection Agency.

Cummins reports having submitted the certification paperwork and other required documentation for both its heavy-duty and midrange engines.

A spokeswoman said the company expects to have certification for its 2010 engines prior to Jan. 1, when Cummins starts producing the new models. She added that Cummins doesnt anticipate any certification issues because "we continually work with the EPA year-round in preparation for the certification process."

Volvo, which supplies engines to Prevost Car, reports submitting its application in July and says its currently being reviewed by the EPA.

Detroit Diesel Corp. said it submitted its first heavy-duty 2010 engine for EPA certification in August. It also expects to have full certification before Jan. 1.

Navistar Inc. said its 2010 system was ready to meet certification but it declined to say when it would submit its application.

All engine manufacturers, with the exception of Navistar, are using selective catalytic reduction, which converts NOx to nitrogen and water vapor in the aftertreatment to meet the 2010 mandate. Navistar is using what it calls advanced EGR, a stepped-up version of the technology introduced three years ago.

Several engine makers using SCR say they expect fuel economy to increase with their 2010 models.

"Volvos SCR technology for EPA 2010 . . . will deliver increased fuel economy, lower cost of operation and no active diesel particulate filter regenerations, along with near-zero emissions," said a Volvo executive.

Detroit Diesel says its 2010 system could enable customers to recoup all the fuel mileage that was lost through changes made necessary by EPA mandates going back to 1998.

"Weve surpassed 25 million demonstrated miles of reliability testing and fuel-economy enhancement that our customers can expect with BlueTec," said a company spokesman. BlueTec is the brand name of Detroits SCR system.