Mack Trucks is partnering with New York City's Department of Sanitation (DSNY) to explore the viability of using dimethyl ether (DME) as an alternative fuel.
DSNY will assess the suitability of the fuel in waste transfer applications by testing a Mack Pinnacle axle back daycab model equipped with a 13L Mack MP8 engine and Mack mDrive automated manual transmission (AMT) that is modified to run on DME.
Mack made the announcement during a press event in New York City, which included a tour of several DSNY fleet management facilities.
"DME, as a fuel, is not a natural product. It's synthetic," explained Roy Horton, director of product strategy, Mack Trucks. "It is derived from natural gas, methanol or any bio-based fuel source."
The DME-fueled Mack Pinnacle, which has been built and is being prepared to test, delivers 445hp and 1,650 ft/lbs of torque.
"DME answers a lot of the challenges that have been posed by the natural gas industry," Horton said. "When they store (DME) onboard, it's very much like propane. So it's not under high pressure, it's not cryogenically cooled, it doesn't vent, and if you puncture a tank it's not going to explode. There's none of that associated with DME."
Mack officials explained that DME requires only minor modification to the fuel pump. Additionally some seals need to be changed, fuel tanks to carry DME onboard need to be added and a couple of the vehicle's electronics need to be adjusted.
Diesel and DME have comparable cetane numbers, and are anticipated to be priced similarly.
"Our expectation is that DME, from a fuel cost standpoint, is going to be on par with diesel on a diesel gallon equivalent (DGE) basis," Horton said
"When you talk about the complications and the added weight that comes with the exhaust aftertreatment systems for diesel engines today, to meet those regulations, DME gives you another alternative," Horton said.
