Setra S 531 DT Test Vehicle


Dossier de presse de l’essai routier du Setra 531 DT

Ce dossier est disponible uniquement en langue anglaise.

The S 531 DT - compelling elegance, comprehensive safety, overall efficiency and connectivity

  • Double-decker in cosmos red metallic

  • Economical drive system with OM 471 engine and GO 250-8

The test vehicle, in the colour cosmos red metallic, has a length of 14 metres and a height of 4 metres. The double-decker bus is powered by the standard 12.8-litre OM 471 BlueEfficiency Power engine with an output of 375 kW (510 hp). Thanks to its proven efficient and eco-friendly BlueTec 6 exhaust gas aftertreatment system, it is powerful, quiet and fit for the future. Its maximum torque of 2500 Nm is on tap from engine speeds as low as 1100 rpm. The GO 250-8 fully automated manual transmission ensures precise gear selection, fast response times, excellent ride comfort and economic efficiency.

The test vehicle features 4* seat spacing, accommodating 78 passengers on comfortable "Setra Voyage Plus" seats. These are upholstered in Trail fabric in dark evo grey, with the seat backs and side bolsters in red carbon fibre. They are fitted with comfort head restraints in black "Composition" blended leather, which are height-adjustable. Design elements in Vincent prestige red add colourful highlights. The vehicle includes a seat for a tour guide and is furthermore equipped with an on-board kitchen and fully accessible toilet/washroom. Passengers on board the new Setra S 531 DT of the TopClass 500 benefit from a bright and friendly interior, stairs in a totally new design and a newly designed front area on the upper deck. The new Setra double-decker bus is fitted with a Coach MediaRouter. This provides WiFi access that allows passengers to connect their mobile devices to the internet.

Exemplary standard of safety

The S 531 DT features numerous safety systems, such as the Electronic Stability Program (ESP), Adaptive Cruise Control (ART), Lane Assist (SPA), Attention Assist (AtAs) and Tyre Pressure Monitoring (TPM) as well as, for the first time in a bus, the assistance systems Active Brake Assist 4 (ABA 4) and Sideguard Assist (SGA). It is also fitted as standard with a fire extinguishing system in the engine compartment. At night the Setra lights up the road ahead with its integrated LED main headlamps as part of standard specification.

Maximum efficiency, variability, comfort and safety, exciting design: The new Setra S 531 DT double-decker bus

  • Safety: Active Brake Assist 4 and Sideguard Assist feature in a bus for the first time

  • Efficiency: outstanding aerodynamics lower fuel consumption

  • Variability: the new Setra is a bus to meet all needs

  • Comfort: bright interior, convenient stairs, innovative washroom

  • The Setra double-decker bus is "heaven-scent"

  • Design: modern and surprisingly distinct appearance

Maximum efficiency and variability, supreme comfort and the ultimate in safety: the new Setra S 531 DT double-decker bus of the TopClass 500 sets new standards in its class. With superlative aerodynamics, this impressive touring coach is all set to establish new fuel efficiency records in its segment. With its flexible lower deck, it covers the entire scope of applications in touring and line service. The interior boasts an impressive standard of comfort. Finally, the use of Active Brake Assist 4 and Sideguard Assist on board the new double-decker bus will mark the world premiere for these assistance systems in the bus and coach segment. These systems further enhance the already high standard of safety. All of this is cloaked in a fascinating design with its own distinct stamp.

Safety: Active Brake Assist 4, Sideguard Assist feature in a bus for the first time

The highest safety standards thanks to group technology - the premium brand's new double-decker comes as standard with long-life LED headlamps which are easy on the eyes. The emergency braking system Active Brake Assist 4 (ABA 4) is being introduced in the bus and coach sector for the first time ever on board the S 531 DT. In addition to the previously available functions – maximum full-stop braking in response to stationary objects and obstacles moving ahead of the vehicle – it now also incorporates pedestrian detection with automatic braking response. Another world premiere in the bus and coach segment is the use of Sideguard Assist for the blind spot. It employs radar sensors to monitor the lane to the right of the bus along the vehicle's entire length. When the driver turns off, the system warns of pedestrians, cyclists or stationary obstacles in the turning path. Over and above this it provides support out of town when changing lanes on the side opposite the driver.

Efficiency: outstanding aerodynamics lower fuel consumption

The new double-decker bus is tailored for optimum aerodynamics from front to rear. Literally from front to rear: At the front, windscreens with pronounced curvature and large edge radii allow the air to flow around the vehicle, while at the rear recesses and airflow break-away edges guide the airflow in a targeted manner. The development engineers have attended to the most minute details: the windscreen wiper on the upper deck is vertical in its rest position, for example – a feature adopted from motorsport. These measures result in a drag coefficient of Cd = 0.35 - a new benchmark for this segment. The aerodynamics provide the basis for record-breaking fuel consumption, which drops by around seven to ten percent compared to the predecessor model, according to the type of use. Depending on the mileage covered, this adds up to savings of several thousand litres of fuel annually.

Variability: the new Setra is a bus to meet all needs

Holiday travels, long-distance regular services, stylish bistro buses, inter-city lines – the new Setra covers all conceivable types of use for a bus on this scale. The variable lower deck provides the basis for this versatility, together with the scope for individual appointments and seating which is characteristic of the brand. Thanks to a entirely new design, the platform on the bottom deck on the right as seen in the direction of travel can be omitted if the customer so desires. This results in new options: wheelchair bays, installations for bistro buses, a demountable platform with pram area for inter-city lines or, with platform, the classic seating for touring purposes. The available diversity is also manifest in the cockpit: customers can choose between the elegantly functional cockpit from the Setra ComfortClass 500 and the luxurious cockpit from the TopClass 500.

Comfort: bright interior, convenient stairs, innovative washroom

With plenty of light and a modern design, the bright interior of the new Setra makes a spacious impression. The stairs connecting the lower and upper deck are particularly eye-catching. Glazed on the outside, they feature panelling consisting of translucent acrylic plastic on the inside. Evenly spaced two-tone steps with individual lighting, landings and continuous handrails give passengers a sense of security when going up and down the stairs. The washroom in a totally new design is also worthy of note. Its installations are arranged diagonally, making maximum use of the available space. The gleaming white upper areas of the furnishings and the pleasant LED lighting are reminiscent of a modern bathroom.

Number one for safety: first bus worldwide to feature Active Brake Assist 4 and Sideguard Assist

  • Setra – tradition-bound to maximum safety

  • Fire extinguishing system as standard

  • World first in the bus and coach segment: Active Brake Assist 4 brakes in response to pedestrians

  • World first in the bus and coach segment: Sideguard Assist provides warnings during cornering and turning off

  • Sideguard Assist also helps when changing lane

Buses are among the safest means of transport. Setra makes them even safer, the new Setra TopClass S 531 DT setting benchmarks with its assistance systems. The use of the Active Brake Assist 4 emergency braking system and Sideguard Assist on board the new double-decker marks the world premiere for these features in the bus and coach segment.

Setra – tradition-bound to maximum safety

ABS, ABA 4, ART, AtAs, BAS, DBL, ESP, TPMS and more besides – the scope of standard and optional equipment for the new Setra reads like an A to Z of the latest assistance and safety systems. This fits into a long tradition at Setra: in 1955 the brand was among the pioneers of independent wheel suspension on buses and coaches, in 1964 it was the first to introduce the retarder as a wear-free auxiliary brake and a few years later it championed disk brakes. Back in 1981 Setra was already optionally installing the ABS anti-lock braking system on all buses and coaches. In 1984 it became the first brand in Europe to fit ABS as standard. Introduction of xenon headlamps as standard in 2001 in the then new TopClass 400, followed in swift succession by the ESP Electronic Stability Program, adaptive cruise control, Continuous Braking Limiter, Lane Assistant and the Front Collision Guard – the highest safety standards courtesy of Daimler Group technology. Setra most recently introduced the option of integrated LED headlamps at the end of 2015.

As a result, the new double-decker buses even comes with LED headlamps as standard. The light from these headlamps is similar to daylight and is less tiring on the eyes. Their durability and their virtually undiminished luminous intensity throughout their service lives are additional benefits of relevance to safety.

The Setra double-decker bus is "heaven-scent"

An optional fragrance dispensing system takes the already pleasant climate on board the new Setra to new heights. When the ignition is turned on and door one is opened, or when a door is left open, a fragrance generator automatically dispenses a discreet and unobtrusive yet very pleasant scent. In this way a fresh yet unobtrusive aura welcomes guests on board and encourages them to feel at their ease. The main components have been adopted from the Mercedes-Benz S-Class. There are six fragrances to choose from, ranging from fresh and sporty to a heavier scent reminiscent of leather.

Design: modern and surprisingly distinct appearance

The new double-decker bus belongs to the Setra TopClass 500. Within the 500 model series it is nevertheless in a class of its own, on account of its broad spectrum of applications and its diverse scope of equipment and variants. This is documented by its modern and distinct appearance. The Setra's face with its dark front panel and silver brand lettering clearly originates from the TopClass 500. As a new feature, the two windscreens are seamlessly joined together and structured by an aluminium bar. On the side wall the designers have adapted the brand's hallmark "La Linea" aluminium strip. Which now extends horizontally along the edge of the roof. The extensive glazing is highlighted by a counter-sweep at the level of the rear stairs, which adds a dynamic touch and features an aluminium surround. The panelling of the upper deck now appears to hover like an island on the glass. Underneath, an aluminium logo plaque above the front wheel arch provides a break in the waistrail on the lower deck. Side fins with airflow break-away edges and the tail lights of the 500 model series frame the rear end. On the new double-decker bus the two vent grilles for the engine have been joined together. Above these, the black grille of the integrated TopAir air conditioning system makes its mark. The chrome-plated logo plaque featuring the brand lettering from the TopClass 500 catches the eye under the rear window – a perfect finishing touch for a spectacular bus.

Fire extinguishing system as standard

Traditionally safety is number one on the list of priorities for Setra, a fact underscored for example by the fire extinguishing system fitted as standard equipment in the new double-decker bus. Not required by law in touring coaches until mid 2019, in the S 531 DT the system is already included from the start of series production as part of the standard equipment.

The extinguishing process is activated via a loss in pressure in a detection line, e.g. due to intense heat. As part of this, the extinguishing liquid is forced through the nozzles of the distribution system and sprayed as a high-pressure water mist in the engine compartment. In this way the oxygen is dispelled within fractions of a second, thus depriving the fire of its supply basis. The surface of the components is cooled and the possibility of reignition effectively prevented. The extinguishing agent runs through the entire engine compartment. As part of this the individual nozzles are directed towards components which reach higher temperatures, such as the turbocharger, oil filter module and auxiliary heater for example.

The fire extinguishing system is certified by TÜV and already achieves advance fulfilment of the statutory provisions and test requirements pursuant to Regulation UN R107/06 Supplement 4, which will be binding for class 3 coaches first registered from 10.06.2019.

Pendulum impact test similar to ECE-R-29 complied with voluntarily

Active safety, i.e. accident prevention, is a prime concern for a double-decker bus with up to 83 passengers on board, hefty dimensions and a permissible gross weight of 26 t. Should an accident nevertheless occur, driver and passengers benefit from the highest possible standard of passive safety. The previous Setra double-decker bus already benefited from a reinforced framework following its comprehensive overhaul in the autumn of 2015, thereby voluntarily meeting the requirements of the pendulum impact test in accordance withECE-R-29. Setra furthermore provides rescue services with online rescue data sheets for all its buses and coaches.

Emergency braking system Active Brake Assist can save lives

The emergency braking system Active Brake Assist (ABA) is an outstanding assistance system. Its original version was introduced in the Setra TopClass 400 around ten years ago, since when it has benefited from ongoing further development. The emergency brake assist system AEBS, which in the meantime has been prescribed by law for class 3 coaches, must already guarantee a significant reduction in speed in response to both moving and stationary obstacles. The current Active Brake Assist 3 (ABA 3) already significantly exceeds the requirements and also brakes the coach to a standstill by full brake application on detecting stationary obstacles. ABA 3 has been available for the Setra S 431 DT double-decker bus since 2015. Touring coaches with emergency brake assist system are thus not only able mitigate the consequences of a serious accident but are actually even able to avoid such accidents, within the given physical limits.

World first in the bus and coach segment: Active Brake Assist 4 brakes in response to pedestrians

A new chapter is now being written in the history of assistance systems: the Setra S 531 DT is the first bus in the world to feature the emergency braking system Active Brake Assist 4 with pedestrian detection – a further milestone in the development of assistance systems.

The outstanding feature of Active Brake Assist 4 is that it warns the driver of imminent collisions with moving pedestrians and simultaneously automatically initiates partial braking. It is the first system of its type worldwide to perform such functions. This enables the driver to avoid a collision by means of maximum full-stop braking or a steering manoeuvre.

Active Brake Assist 4 thus constitutes a further development of well-proven Active Brake Assist 3, incorporating an additional warning and partial braking to enhance the safety of pedestrians. Its mode of operation and displays correspond to ABA 3. Unlike when braking for moving and stationary obstacles, there is no warning cascade prior to partial braking for moving pedestrians: the acoustic and visual warnings occur at the same time as partial braking.

Long- and short-range radar systems detect pedestrians, cars and objects

The long-range radar of Active Brake Assist 4 detects vehicles and obstacles in a direct line in front of the bus up to a distance of 250 m and pedestrians up to a distance of 80 m. Motorcycles, mopeds and cyclists are detectable up to a distance in between these two ranges (160 m). The maximum beam angle is 18 degrees. The short-range radar has a range of 70 m. The wide beam angle of 120 degrees additionally enables Active Brake Assist 4 to detect vehicles and moving pedestrians at the sides of the area in front of the vehicle, whereby the range of vision is dependent on the topography, the course of the road, weather conditions and ambient influencing factors, such as pedestrians moving quickly into the traffic area or concealed pedestrians.

Active Brake Assist 4 is able to detect moving pedestrians in virtually any traffic situation, for example if they cross the bus's lane, emerge from behind an obstacle or are moving along the vehicle's lane. Pedestrians are also detected within the range of the radar system when the vehicle turns off to the left and right. The warning and braking reactions to stationary and moving obstacles are effective across a speed range from 0 to 100 km/h, while the automatic warning and braking reactions of the pedestrian detection system apply up to a speed of 50 km/h.

The bus driver then decides on any further actions. The driver can override the system at any time as necessary, by means of a steering movement, kickdown or emergency braking, for example. If the driver does not brake firmly enough, the braking intensity of Active Brake Assist 4 takes precedence.

Multi-mode radar with improved range and performance

The basis for Active Brake Assist 4 with the additional pedestrian detection function is provided by a new generation of radar technology. This is also used in the current passenger cars and trucks from Mercedes-Benz, demonstrating the close cooperation within the group.

The advantage of a radar system is that it operates independently of the prevailing light conditions and also largely independently of weather conditions. Radar determines distances and relative speeds extremely precisely, and is also able to "see" at night and in rain and fog. Vehicles, pedestrians and objects are recognised on the basis of a radar signature. This involves analysis first and foremost of the form and reflection.

The new radar generation takes the form of electronically scanning multi-mode radar. This offers markedly improved range and performance. For the first time, the long-range radar now operates independently of the set driving level and is able to adapt continuously to changing inclination of the vehicle as a result of suspension or load statuses.

World first in the bus and coach segment: Sideguard Assist provides warnings during cornering and turning off

Right turns in urban traffic are among the least pleasant tasks for drivers, as they are required to heed traffic lights and signs ahead while simultaneously observing oncoming and crossing traffic and keeping an eye on pedestrians and bike riders at the side. In addition, the traffic situation can change in a matter of seconds, and cyclists and pedestrians are not always aware that a bus driver may possibly not be able to see them. With this in mind, Setra is now the first bus and coach brand to offer the Sideguard Assist with pedestrian detection. Available for a year now on board Mercedes-Benz trucks, the time is currently ripe to introduce Sideguard Assist for buses and coaches as well.

The objective: continual information, warnings as necessary

Sideguard Assist operates in several stages: it first of all informs the driver when a relevant object is located in the warning zone. In a second stage the driver receives a warning if they initiate or continue an action and a danger of a collision arises.

If there is a moving object in the side monitoring zone the driver is provided with a visible warning. An LED in the shape of a triangle lights up at the driver's eye level in the outside mirror on the co-driver's side. The lamp draws the driver's attention intuitively towards the situation alongside the vehicle. If the sensors detect the risk of a collision, an additional visual warning is given: the LED flashes brightly several times in red. After two seconds, it remains permanently illuminated in red. A haptic warning in the form of a vibration in the driver's seat is additionally provided, as with the Lane Assistant.

A visual and haptic warning also occurs if the sensors additionally detect a stationary obstacle, such as a traffic light or a bollard, in the bus's turning curve during cornering. Collisions can be avoided in this way. The tracking pattern curve warning system functions from walking pace up to 36 km/h. The other functions of Sideguard Assist are available from walking pace up to 100 km/h.

For the purposes of its warning cascade, Sideguard Assist also analyses actions by the driver, for example activation of the indicator on the co-driver's side or the steering movement when moving off, and the distance from a moving or stationary object is assessed continuously while the truck is on the move. Sideguard Assist also warns the driver of any obstacles when they turn off without activating the indicator, for example.

The driver retains full responsibility and remains in control of the situation at all times and is able to take any course of action which appears appropriate.

Sideguard Assist also helps when changing lane

The new Sideguard Assist offers even more functions: at speeds above 36 km/h and up to the maximum permissible speed it provides the driver with warnings as an assistance system during lane changing. The driver is also informed of any object on the co-driver's side and a corresponding warning is output if the driver activates the indicator. This means that Sideguard Assist provides support when changing lane, for instance when overtaking a cyclist in an extra-urban setting, or when changing lane on multi-lane roads.

The radar sensors monitor the entire area on the co-driver's side

The core of Sideguard Assist is a radar sensor system with two short-range radar sensors in the wheel arch of the front axle on the co-driver's side. The side monitoring zone has a width of 3.75 m. The system is oriented so as to cover the entire length of the bus. Its range additionally covers the area two metres in front and behind the vehicle. Above 36 km/h, the scanned area is increased to up to 5 m to the front and as much as 15 m to the rear, in the interests of safe lane changing.

Technical data and equipment of the Setra S 531 DT in touring coach specification (NU-DT 5311)

Vehicle data


Length: 14 000 mm


Width: 2550 mm


Height: 4000 mm


Wheelbase, front axle-drive axle: 6700 mm


Wheelbase trailing axle-drive axle: 1350 mm


Overhangs: 2705 mm front/3245 mm rear


Turning circle: approx. 23 100 mm


Tank capacity: approx. 480 l


AdBlue tank capacity: approx. 40 l


Luggage compartment capacity: 8.4 m³


Drive and chassis


Engine, cylinders: OM 471, 375 kW (510 hp), 6 inline


Displacement: 12.8 l


Torque: 2500 Nm (1100 rpm)


Exhaust-gas aftertreatment: controlled exhaust gas recirculation, SCR technology, closed particulate filter


Emissions standard: Euro VI


Final-drive ratio: i = 3.583


Transmission: 8-speed MB GO 250-8 (PowerShift)


Retarder: Voith secondary water retarder


Front axle: Setra-produced with MB wheel head


Drive axle: MB RO 440


Steering: ZF Servocom 8098


Safety and assistance systems


Electronic Stability Program (ESP) incl. acceleration skid control (ASR), Brake Assist (BAS), Lane Assistant (SPA), Tyre Pressure Monitoring (TPM), adaptive cruise control (ART) with Stop&Go, Active Brake Assist 4 (ABA 4), Predictive Powertrain Control (PPC), Eco Driver Feedback (EDF), Attention Assist (AtAs), start-off assist, frequent-stop brake with starting-off lock, stabiliser bar on front and rear axle, electronic level control (ENR)



Seats: 78, upholstery Setra Voyage Ambassador, multipiece seat backrest in Composition/fabric combination, 2-point seat belts on all passenger seats (driver and tour guide seat plus first seat row in the upper deck with 3-point seat belts), passenger seats along the aisles with sideways adjustment, footrests on seat frame bases, folding tables, driver's seat Isringhausen NTS 2 (type 6860), one tour guide's seat

Equipment includes


Coach Multimedia System (CMS) audio/video system with DVD player

Coach Media Router for internet access and media streaming

Service sets with air vents and LED reading lamps

LCD video monitors, screen diagonal of 48 cm (19 inches)

EvoCool TopAir air conditioning system

Fire extinguishing system with detection line in engine compartment

LED low-beam and high-beam headlamps

High-pressure headlamp washing system

Cornering light function

LED daytime running lamps

Ambient lighting for reversing

Rain/light sensor

Video camera over door two

Reversing camera with integrated washing system

Fleetboard Bus fleet management system

Multifunction key with Remote Bus app

New telematics platform

Comfort Plus cockpit

Galley with coffee machine (2 x 40 cups)

TopSky glass roof


Entry fragrance dispensing system



cosmos red metallic

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