Natural gas-fuelled Econic trucks with Allison transmissions help Stuttgart win battle against fine dust pollution
22nd May 2018

Municipal refuse hauler expanding natural gas fleet fourfold as diesel bans loom

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 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 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 centres 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 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.

Overview Mercedes-Benz Econic NGT 6 x 2/4 with Allison 3500 fully automatic transmission (3000 Series™)

End user AWS Abfallwirtschaft Stuttgart
Chassis (manufacturer / type) Mercedes-Benz Econic NGT 6 x 2/4
Engine Mercedes-Benz M 936 G, 7,7 l cubic capacity
Engine output 222 kW (298 hp)
Torque 1.200 Nm at 1.600 rpm
Transmission Allison 3500 fully automatic transmission
Exhaust gas class EURO 6
Wheelbase 3.900 mm
Gross vehicle weight 26 tonnes

Image – © Allison Transmission. With its deep first gear ratio and hydraulic torque converter, the Allison 3500 enables ideal performance for the demanding Stuttgart topography.

Image – © AWS Abfallwirtschaftsbetrieb Stuttgart. “The new Econic NGT with Euro 6 natural gas engine and Allison fully automatic transmissions are environmentally friendly, quiet and virtually free of any particulates,” said Dr. Thomas Hess, Managing Director AWS Abfallwirtschaft Stuttgart.

Image – © Daimler AG. The 10 refuse trucks are equipped for the first time with the new Euro 6 M 936 G natural gas engine, with 7.7 litre cubic capacity and an engine output of 222 kW (298 hp), mated with an Allison 3500 fully automatic transmission.

Image – © Daimler AG. Allison’s torque converter technology supports the natural gas engine at vehicle launch, multiplying engine torque and smoothly delivering power to the drive wheels. As a result, the vehicles deliver superior performance, while increasing fuel efficiency.

Image – © Daimler AG. So far, the Econic NGTs have proven themselves at municipal owner-operated company AWS. The vehicles are reliable and easy to manoeuvre and operate.

Image – © Daimler AG. The 10 Mercedes-Benz Econic NGT should help to reduce emissions and fine dust pollution in the city with a population of 600,000.

About Allison Transmission

Allison Transmission (NYSE: ALSN) is the world’s largest manufacturer of fully automatic transmissions for medium- and heavy-duty commercial vehicles, and is a leader in electric hybrid-propulsion systems for city buses. Allison transmissions are used in a variety of applications including refuse, construction, fire, distribution, bus, motorhomes, defense and energy. Founded in 1915, the company is headquartered in Indianapolis, Indiana, USA and employs approximately 2,700 people worldwide. With a market presence in more than 80 countries, Allison has regional headquarters in the Netherlands, China and Brazil with manufacturing facilities in the U.S., Hungary and India. Allison also has approximately 1,400 independent distributor and dealer locations worldwide. For more information, visit

About AWS Abfallwirtschaft Stuttgart

As a municipal service company in the state capital Stuttgart, AWS Abfallwirtschaft Stuttgart disposes and utilize residual, paper, and organic waste and exploits recyclable materials.

These services are supplemented by a collection service for bulky waste and green waste as well as a container service for major sources of waste. Further focuses are street cleaning and winter services. AWS has seven depots, five recycling depots, a landfill site and operates a fleet of approximately 900 vehicles and an own workshop. The company employs around 792 people. For more information about AWS Abfallwirtschaft Stuttgart, visit