Press Information

September 2012

World premiere: Mercedes-Benz Aerodynamics truck and trailer save fuel and relieve the burden on the environment

•  Aerodynamicstrailer saves 2000litres of diesel and five tonnes of CO2 emissions per year

•  Spoilers, trim panels and diffusers lower wind resistance

•  Air resistance falls by 18 percent, consumption by 4.5 percent

•  Saving the best for last: the rear taper of the Aerodynamics trailer

•  Practicable down to the last detail

•  Future EU length regulation allows rear taper

•  Aerodynamics truck lowers fuel consumption by three percent

•  Box body: smooth walls, rounded edges

•  Good aerodynamics thanks to extensive experience

Daimler Communication, 70546 Stuttgart/Germany
Mercedes-Benz – A Daimler Brand

Stuttgart/Hanover – To further reduce fuel consumption in truck/semitrailer combinations, Daimler launched its "Aerodynamics Truck & Trailer" initiative. As part of this, engineers researched the aerodynamics of current vehicle concepts and then developed two innovative and at the same time practicable solutions. The solutions are relatively easy to put in place in the short term. Last year, the tractor/trailer combination was a spectacular design study, this year it is already a reality: with the new Mercedes-Benz Aerodynamics trailer, a long-haul tractor unit can save approximately 2000 litres of diesel annually, thereby saving its operator nearly 3000 euros in expenses. At the same time, the environment is spared more than five tonnes of CO2 emissions each year. The second vehicle, the Mercedes-Benz Aerodynamics truck, is a rigid truck for long-distance haulage and short-radius distribution operations. It saves between 300 and 600litres of diesel annually and up to 1.5 tonnes of CO2. The Aerodynamicstrailer and Aerodynamicstruck will celebrate their world premiere at the International Motors Show for commercial vehicles (IAA) at the entrance to Hall14/15.

Daimler Communication, 70546 Stuttgart/Germany
Mercedes-Benz – A Daimler Brand

Air resistance falls by 18 percent, consumption by 4.5 percent

From the vision of the 2011 study, the trailer has become a reality in 2012. The Aerodynamics trailer designed and developed by Mercedes-Benz lowers the air resistance of the entire tractor/
semitrailer combination by approximately 18 percent. According to the engineers' experience, this results in a fuel consumption reduction on long-haul journeys of approximately four to five percent in real conditions. Intensive measurements in the wind tunnel with a 1:2.5-scale model confirmed the arithmetic assumptions.

In the next step, real-world tests conducted by Mercedes-Benz on the road proved that a tractor/semitrailer combination with a gross weight of 40 tonnes consisting of a Mercedes-Benz Actros – currently offering the best aerodynamics in a series production truck – and the aerodynamically optimised Aerodynamics trailer can achieve fuel savings of 4.5 percent in long-haul usage. In the case of an average annual mileage of 150,000 km for a long-distance truck, this means a reduction in diesel consumption of around 2000 litres and relieves the burden on the environment by more than five tonnes of CO2 annually. In real terms, trucks which are subject to toll charges on German motorways (12 t and above) cover around 25 billion kilometres which corresponds to 300 million litres of diesel that can be saved in a year, as well as over 800,000 tonnes of CO2 emissions.

Actros StreamSpace tractor unit remains unchanged

The tractor unit, here the new Mercedes-Benz Actros with StreamSpace cab, remains unchanged. The new Actros is already aerodynamically optimised. It will merely be equipped with an air deflector on the roof, cab side deflectors and side trim panels between the axles. This aerodynamics package is already available ex factory for heavy-duty Mercedes-Benz trucks in long-haul transport.

Aerodynamicstrailer ready for everyday use – with no restrictions

Not just some futuristic concept, the Mercedes-Benz Aerodynamicstrailer is ready for everyday use, without any restrictions. It is based on a conventional 13.6m freezer box body, with a refrigeration unit at the front end. Whether for ground clearance, approach/departure angle or ease of loading at the rear – the Aerodynamicstrailer meets all the usual requirements of everyday haulage. The box body remains unchanged despite the aerodynamic measures.

The development partners in the IAA project were Daimler Trucks and renowned trailer specialist Schmitz Cargobull. They ensured focus was on everyday suitability. Working closely with designers and engineers from Daimler Trucks, Schmitz Cargobull developed the attachments on their own, based on designs furnished by Mercedes-Benz. These were transformed by Schmitz Cargobull into the actual Aerodynamicstrailer using computer surface data.

Generally speaking, however, the Aerodynamicstrailer is not bound to a particular brand: as it had done at the "Trailer" show in Kortrijk in autumn 2011, Mercedes-Benz once again invites all trailer manufacturers to develop efficient, environmental semitrailers on the basis of the Aerodynamicstrailer.

Based on a design study from Mercedes-Benz

The Aerodynamicstrailer began as a study presented by Mercedes-Benz last autumn at the "Trailer" trade show in Kortrijk, Belgium. Going beyond the Actros, Mercedes-Benz had set its sights on the entire tractor/semitrailer combination.

By way of background, with the new Actros, Mercedes-Benz has introduced the most efficient heavy-duty truck. It proved this in the spectacular Actros Record Run covering 10,000kilometres on European motorways: the Euro VI version of the Actros 1845 achieved a fuel consumption of only 25.9l/100km. Both customer reactions and the latest press trials have confirmed this excellent performance: the new Actros is the most frugal and thus the most environmentally-friendly truck in its class.

There are many reasons for this. The new Mercedes-Benz Actros has a completely redeveloped, fully automatic powertrain, revolutionary assistance systems such as the GPS-controlled Predictive Powertrain Control (PPC) cruise control system and last but not least, after 2600 hours in the wind tunnel, a sophisticated aerodynamic design. This leaves little room for further significant fuel savings accomplishments in the near future.

As the Aerodynamicstrailer shows, ultimate efficiency in a semitrailer is only achieved with the perfect combination of tractor unit and trailer. Based on the results of the Record Run, a realistic fuel consumption of less than 25 l/100 km is possible for a 40-tonne tractor trailer when a Mercedes-Benz Actros is combined with an Aerodynamicstrailer. Just a few years ago, experts in the field would have dismissed such figures as utopian.

Not just a show vehicle but a realistic semitrailer

The designers and developers from Mercedes-Benz did not rely on unrealistic show effects when combining the new Actros with the Aerodynamicstrailer: this vehicle combination is producible, upholds the framework of coming legal requirements and is absolutely realistic for everyday use under tough road transport conditions.

No change in refrigerator box body dimensions

The Aerodynamicstrailer at the IAA corresponds largely to the Mercedes-Benz study. The basic model is a refrigerator trailer, a typical vehicle for long-distance haulage. Measuring 13.6m long and 2.6m wide with a total height of 4m including the chassis, the familiar box body remains unchanged for the Aerodynamicstrailer.

Spoilers, trim panels and diffusers lower wind resistance

Numerous individual measures on the Aerodynamicstrailer lower the air resistance of the entire tractor unit. A spoiler on the bulkhead of the trailer reduces the distance to the tractor unit, and this itself lowers air resistance by one percent. The spoiler frames the refrigerator unit, with air slots providing the necessary ventilation.

Meanwhile, the plastic side trim panels on the Aerodynamicstrailer contribute an eight percent improvement to the air resistance. As in the design study, they are slightly drawn-in at the front and characterised by an opening at the rear. This steers the air in the direction of the striking rear diffuser.

The diffuser has the shape of a parallelogram and links up with the underbody panelling. Also made of plastic, it improves the wind resistance by a further one to two percent.

The diffuser surrounds the rear underride guard and serves as a mount for the tail lamps. Accentuating the striking Aerodynamics trailer at night are round tail lamps, instead of the multiple compartment lamps typical of the brand. They emphasise the almost sporty design of the Aerodynamicstrailer. The elaborate trim panels on the lamps underline the detailed aerodynamic touches. The same is true for the trim panels of the landing legs beneath the body.

Saving the best for last: the rear taper of the Aerodynamics trailer

An important component of the complete aerodynamic system is the "boat tail", a rear taper measuring up to 400mm in length. It improves the air resistance of the entire tractor unit by a full seven percent. Its elements can be folded away, ensuring the usual easy access to the cargo compartment. The wings of the rear taper are made of aluminium sections and the sides are elegantly curved.

Practicable down to the last detail

The developers of Mercedes-Benz and Schmitz Cargobull paid particular attention to the everyday usability of the Aerodynamics trailer. Its rear aerofoil automatically swings approximately ten degrees upwards during loading and unloading, providing clearance for the doors of the loading portal. When the trailer unit is stationary, electric actuators automatically fold the side wings of the taper onto the door sections. This ensures an opening angle of around 245 degrees when opening up the doors.

It also enables the trailer to negotiate bollards when manoeuvring at loading/unloading docks and to dock at the loading bay for loading and unloading. Even the familiar buffers at the rear are a mark of practicality.

A ground clearance of 350mm for the side trim panels and the approach/departure angle of the Aerodynamicstrailer likewise correspond to the requirements of companies, important for example when negotiating ferry ramps. Engineers and developers also focussed on easy accessibility of the landing legs as well as operation of the control valves and easy operation of the loading portal. A practical pallet box is provided, as are the required side marker lamps.

The hinges on the loading portal are standard parts, as too is the frame structure of the side trim panels. In other words, it will soon be possible to manufacture the Aerodynamics trailer on a commercial scale.

Future EU length regulation allows rear taper

An essential element of the Aerodynamicstrailer is the "boat tail" with a rear taper in the form of flaps. These extend the Aerodynamics trailer by 400mm and are more important for the aerodynamics of a tractor/semitralier combination than unrealistic nose-shaped cab extensions.

Appeals to this effect to lawmakers for a modification of the length regulations did not fall on deaf ears: in May of this year, the EU Commission recommended an extension of the maximum length by up to 500 mm for aerodynamic measures at the rear. Prerequisites: the loading length must not be restricted; when the vehicle is stationary, the extension must fold in to the permitted maximum length of 16.5 m for semitrailers and must not adversely affect use in combined operation.

The Mercedes-Benz Aerodynamicstrailer meets these requirements. The flaps on the rear extension fold in automatically by means of an electric motor when the vehicle is at a standstill. This does not impair the vehicle's manoeuvrability. It is anticipated that the change in length regulations in the EU will become law by early next year.

Aerodynamics truck lowers fuel consumption by three percent

An aerodynamically optimised rigid truck in long-haul transport and short-radius distribution also relieves the burden on the wallet and the environment, as evidenced by the Mercedes-Benz Aerodynamics truck prototype. In this project the aerodynamic engineers and development engineers at Mercedes-Benz took ideas from the Aerodynamicstrailer and applied them to the rigid truck, with vehicle-specific enhancements.

Rigid vehicles can also achieve considerable potential savings: there is a large number of aerodynamically relevant applications even in short-radius distribution. Thus the new Mercedes-Benz Antos was used as the basis vehicle and then developed to offer the best aerodynamic figures possible. Added to this are typical long-haul applications such as furniture or flower transport. This is also true for toll-free rigid vehicles under the 12 t permissible gross weight rating.

Compared with conventional box-type rigid vehicles, the Aerodynamics truck improves aerodynamics by approximately twelve percent. This means a consumption reduction of approximately three percent on trunk roads. In the case of an annual mileage of 50,000 kilometres, this results in a saving of around 350l per year, equivalent to a saving of around 500euros for the operator or just under one tonne of CO2 for the environment. With higher mileages in long-haul transport, the prospects of the Aerodynamics truck are even more favourable.

These projections from the development engineers have been confirmed in practice in initial test drives.

Basis of the Aerodynamicstruck: chassis plus ClassicSpace

The basis of the Mercedes-Benz Aerodynamicstruck is a two-axle platform truck chassis with 18t permissible gross weight rating and the 2.3m wide cab of the Actros ClassicSpace. A cab from the new Mercedes-Benz Antos is also available. Particularly in short-radius distribution, this vehicle sets standards and is available in two cab lengths.

The same goes for the Aerodynamicstruck: good aerodynamics is a standard feature of the cab. The cab side deflectors are from the tried-and-tested accessories range from Mercedes-Benz and fit almost flush with the structure. There is no need for a spoiler on the bulkhead, but the air deflector on the roof is necessary.

Box body: smooth walls, rounded edges

The body is a conventional box with an outside length of 6.5m, a width of 2.55m and an inside height of 2.20m. The outer skin is made of smooth Alucobond plates, which provide little resistance to the wind. In contrast to many aerodynamically unfavourable box bodies, the Aerodynamicstruck has an edge radius of 80mm at the transition of the side walls to the roof and an edge radius of 200 mm at the bulkhead. This ensures a streamlined airflow.

The side trim panels are reminiscent of the Aerodynamicstrailer. Their upper edge fits nearly flush with the box body. On the Aerodynamicstruck as well, the trim panels at the rear are drawn in and direct the air towards a rear diffuser, which fully encompasses the underride guard. An edge radius of 200mm at the bottom end of the side trim panels provides a soft transition without separation of air flow towards the underside.