Mack Trucks hosted members of the media in Austin, Texas, last week to discuss its powertrain offerings, sharing additional information about its single-package exhaust aftertreatment system (EATS), its newest models of the mDrive HD automated manual transmission and 2017 engine options.
“We began this journey – this development journey – that produced these products … about three years ago. That’s when we started working on the new greenhouse gas ’17,” said Roy Horton, director of product strategy, Mack Trucks. “At the same time that we were going through those activities to meet the new requirements of the regulation, we decided to update our powertrain platform.”
ClearTech One
ClearTech One, Mack Truck’s single-package EATS, allows the diesel particulate filter (DPF), selective catalytic reduction (SCR) technology and diesel exhaust fluid (DEF) dosing system to be combined into one unit, giving customers more room for chassis-mounted equipment or larger fuel tanks without the need to lengthen the wheelbase.
“ClearTech had four main objectives during the development activities – improve the efficiency of the unit; reduce and improve the weight of the unit; improve the chassis packaging on all of the truck combinations that it’s used on; and reduce the overall service time that it takes to replace DPF filters,” Horton explained. “So with those four items in mind, this is where we are. We have an all-new exhaust aftertreatment system design.”
According to Horton, ClearTech One is 11” shorter and 17 lbs lighter than the company’s current system. He added that the unit no longer needs to be dismounted during service intervals, which saves time and gets trucks back in operation sooner.
“ClearTech One is standard on all MP7 and MP8 engines used in conventional vehicles,” Horton said, noting Mack’s two-unit exhaust aftertreatment system is still available for certain truck configurations.
Transmission offerings
Mack is now offering the mDrive HD 13-speed and mDrive HD 14-speed as part of its lineup of automated manual transmissions (AMT).
Available in direct or overdrive configurations, the mDrive HD 13-speed offers a low reduction gear ratio designed for easier starting on steep grades or when the truck is under heavy load. The mDrive HD 14-speed adds a second ultra-low-speed reduction gear designed for curb pouring applications or low-speed, heavy-haul maneuvering. The company says both transmissions offer up to four reverse gear ratios.
“These are important because they are tailored to our vocational applications,” Horton said. “We’re not just using mDrive HD 13- and 14-speed inside of vocational. We’re also using it on the highway side to improve the startability for those heavy-haul applications.”
Horton hinted that additional news regarding the mDrive will be announced in the coming weeks.
MP series engines
Mack also shared details about its 2017 MP series of engines. The company said the new engines boost fuel efficiency from 2.1 to 8.8 percent compared with prior model year engines. Mack’s 11L MP7 and 13L MP8 engines both feature an updated wave piston design that raises the compression ratio and enables more complete combustion of fuel, while a common-rail fuel system injects fuel more precisely.
A number of additional improvements were made to both engines, including a new two-piece valve cover, shimless rockers and a low-pressure fuel system with an integrated aftertreatment dosing module to reduce maintenance needs. An updated, double-walled EGR flow sensor helps reduce condensation and soot buildup in cold weather, while a new intake throttle enables a faster warmup when the engine is started.
For customers with long-haul applications, Mack is offering an MP8 engine model with a turbo compounding system. The company explained turbo compounding converts waste energy from the exhaust into mechanical energy that is fed back to the engine. The system increases horsepower and fuel efficiency.
“Our main feature here that we’re doing is changing the engine, taking away the unit injection pumps and bringing in a common rail system – so it’s a high-pressure common rail system that we’re using on the engine,” said Mack marketing product manager Stu Russoli, adding that a quieter ride is provided by replacing the pump with the common rail.
The Mack MP8 with turbo compounding is available exclusively with Mack’s Super Econodyne downspeeding package.
