Municipal refuse hauler expanding natural gas fleet fourfold as diesel bans loom
STUTTGART, Germany – In a major expansion of its efforts to reduce particulate and noise emissions, AWS Abfallwirtschaft Stuttgart plans to acquire 30 additional Mercedes-Benz Econic NGT (Natural Gas Technology) refuse trucks equipped with Allison 3500 fully automatic transmissions.
In December 2016, the municipally-owned company put into service the first of 10 Allison-equipped Mercedes-Benz NGT trucks now in its fleet. Due to its location in a valley basin, Stuttgart is particularly vulnerable to fine dust, exhaust gas and noise emitted by diesel engines.
"We will actively help to alleviate the emission problem in our inner city," said Dr. Thomas Hess, Managing Director AWS Abfallwirtschaft Stuttgart. "The new Econic NGT with Euro 6 natural gas engine and Allison fully automatic transmissions are on route environmental friendly, quiet and virtually free of any particulates."
Natural gas engines are more responsive when joined to an Allison Automatic. Torque converter technology multiplies engine torque to significantly improve startability and launch, even on steep grades. With the torque converter and a deep first gear ratio, the Allison 3500 enables ideal performance in variable terrain.
"Our drivers appreciate the smooth and easy launch of the vehicles with Allison transmissions, even under load," Hess said. "Due to the topographical situation of Stuttgart, with large height differences, this is a great advantage and simplifies the daily work."
Allison transmissions allow alternative-fuel engines to operate at a more consistent engine speed, maximizing efficiency by eliminating torque interrupts of a manual or automated manual transmission. An optional output retarder improves braking, resulting in reduced downtime and maintenance costs.
In addition, the helical gears of the Allison transmission in combination with the natural gas engine help to reduce noise compared with a diesel engine. According to measurements in Stuttgart of trucks during a drive cycle, the noise emissions of the Mercedes-Benz Econic NGT are 78 dBA, while the measuring instrument displays 80 dBA for a typical Euro 6 diesel engine.
Throughout Europe, governments have banned or are considering bans on diesel vehicles in city centers as a way of reducing pollution. Although some fleet operators are exploring fully electric vehicles, vehicles using alternative fuels such as natural gas are less expensive to acquire and are already supported by fueling infrastructure. Besides virtually eliminating particulates, Mercedes-Benz Econic NGT vehicles emit about 23 percent less carbon dioxide than Euro 6 diesel engine, according to tests performed by Daimler.
The AWS refuse trucks are equipped with the new, 7.7-liter Euro 6 M 936 G natural gas engine that produces 222 kW (298 hp). Since its market launch in 1998, the Econic series has been a constant in AWS Stuttgart fleet. Currently, a total of 62 Econic trucks –including the 10 new Econic NGT models – are in use by AWS.