LAS VEGAS – Both Mercedes-Benz diesel engines sold in Freightliner heavy- and medium-duty trucks will be fitted with cooled EGR (exhaust gas recirculation) to meet federal 2004 emissions requirements. The company also told dealers meeting here that early next year it will introduce an automated version of its six-speed manual transmission for its medium-duty Business Class M2.
The heavy-duty 12.8 L MBE4000 and medium-duty MBE900 were not required to meet the Oct. 2002 emissions deadline set as part of a court case brought by EPA against a number of diesel engine makers, and Freightliner was able to continue selling those engines without advanced emissions-reduction systems such as cooled EGR. Now, however, they must comply with the originally scheduled Jan. 2004 deadline for achieving the lower emissions levels.
In conjunction with cooled EGR, the two ’04-compliant MB diesels will use fixed-vane turbochargers with waste gates instead of the variable vane turbocharger design used by some other engine makers. The major benefit is lower cost.
New electronic controls for both will also add full diagnostics and the ability to use Detroit Diesel’s Diagnostic Link software.
The changes will add approximately $3,000 to the cost of the HD diesel and $2,000 to the medium-duty model. Fuel economy will drop by no more than 2%, according to Freightliner officials.
The MBE4000 will retain current power and torque ratings, ranging from 350 to 450 hp and peak torques of 1350 to 1550 lbs. ft.
The MBE900 continues to come in 4- and 6-cyl. versions, but will two additional displacement options, 7.2L in 6-cylinders and 4.8L in 4-cylinders. Power ratings will range from 170 to 330 hp with peak torques of 420 to 1,000 lbs. ft.
The Mercedes-Benz Automated Gear Shift (AGS) transmission used electronic controls and hydraulics to manage all gear changes. The “two-pedal” design is based on the company’s 6-speed manual and will be available with the MBE900 in the Business Class M2 early next year in two torque ratings – 520 lbs. ft. and 660 lbs. ft.
Combined with Freightliners SmartShift lever, drivers can choose to let the transmission make all shifts or choose to control shifts manually. Benefits are said to include better fuel economy and less clutch wear compared to manual models. Cost of the automated manual is also said to be significantly lower than automatic constant torque transmissions.