In its efforts to reduce dust pollution and noise emissions, Stuttgart acquires 30 Mercedes-Benz Econic NGT (Natural Gas Technology) refuse trucks equipped with Allison 3500 fully automatic transmissions.
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 engines and Allison fully automatic transmissions are 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 start-ability and launch, even on steep grades. With the torque converter and a deep first gear ratio, the Allison 3500 achieves 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 enable alternative-fuel engines to operate at a more consistent engine speed, maximising efficiency by eliminating torque interrupts of a manual or automated manual transmission. An optional output retarder will improve braking, resulting in reduced downtime and maintenance costs.
Additionally, the helical gears of the Allison transmission in combination with the natural gas engine will reduce more noise compared to 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 centres in order to reduce 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 fuelling infrastructure. Besides virtually eliminating particulates, Mercedes-Benz Econic NGT vehicles emit about 23 percent less carbon dioxide than Euro 6 diesel engines, according to tests performed by Daimler.
The AWS refuse trucks are equipped with the new, 7.7-litre 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 the AWS Stuttgart fleet. Currently, a total of 62 Econic trucks, including the 10 new Econic NGT models, are in use by AWS.