Technology of tomorrow in a bus of today
New BlueEfficiency Power engine, new transmission, new cockpit, new safety features
Easily identified by the newly arranged ventilation grilles
Clear instrument layout, no gearshift lever
Practical crawler function for manoeuvring
Powerful start-off, fast and comfortable transmission
Well-balanced suspension, engine with bite
New Active Brake Assist 2 brakes if stationary obstacles are detected
Stuttgart/Eltville – Mercedes-Benz Buses once again demonstrates its technological leadership: the premium high-decker Travego Edition 1 is the first touring coach to meet the Euro VI emissions standard. At the same time it is the world's first production bus to comply with the currently most stringent emissions standard: the first examples of the top-of-the-range model have already been delivered. The Travego Edition 1 comes with a new BlueEfficiency Power engine, a new transmission and cockpit, and unique safety features such as Active Brake Assist 2.
Technology of tomorrow in a bus of today
The Mercedes‑Benz Travego Edition 1 ushers in a new era for touring coaches. This flagship model from Mercedes-Benz Buses is the first touring coach to meet the coming Euro VI emission standard, which becomes mandatory from the beginning of 2014. The Travego Edition 1 is powered by the new BlueEfficiency Power engine generation and features a new transmission with a new gearshift, a further upgraded, ergonomically optimised cockpit and new safety features. This means that customers with an eye to the future can already become trendsetters in environmental compatibility with the flagship model from Mercedes-Benz.
High-torque Mercedes-Benz engine from the new BlueEfficiency Power generation
The engine of the Travego Edition 1 is a vertically installed in-line six-cylinder from the new OM 471 series. It has a displacement of 12.8 litres and delivers 350 kW (476 hp) at 1 800 rpm. The impressively high maximum torque is 2 300 Nm at 1 100 rpm. This data and the power delivery characteristics of the new engine ensure superior performance on the road.
The engine features the unrivalled common-rail injection system with X-PULSE pressure boosting. This leads to extremely precise fuel injection with cylinder-selective control, high injection pressures of up to 2 100 bar and freely configurable injection. The new engine is a precondition for low fuel consumption, low exhaust emissions and smooth running. In the Travego Edition 1 the engine of tomorrow is already available today.
Additional advantages stem from the effective, three-stage engine brake and the asymmetrical turbocharger. Despite exhaust gas recirculation, this ensures a fast response to the accelerator for agile driving characteristics. The torque curve of the new engine allows unusually low, fuel-saving engine speeds. The responsiveness and enormous pulling power of the new engine are remarkable: the engine already delivers practically all of its 2 300 Nm of torque at 1 000 rpm, and 2 000 Nm of torque at as little as 900 rpm.
Conflict of aims between emissions and fuel consumption resolved
The particularly stringent requirements of the coming Euro VI standard with respect to nitrogen oxide emissions (NOX) generally conflict with demands for even lower particulate emissions and low fuel consumption. Mercedes-Benz resolves this conflict of aims with the new, unique X-PULSE injection technology, as well as sophisticated exhaust gas aftertreatment. To this end BlueTec engine technology, which has proved its worth in more than 500 000 vehicles to date, is combined with SCR, AdBlue injection, exhaust gas recirculation and a particulate filter.
The new in-line engines impress with their low consumption and particularly low pollutant emissions. Recirculation of cooled exhaust gases reduces the nitrogen oxides generated during combustion, which allows the consumption of AdBlue to be reduced by 40 percent compared to Euro V. The AdBlue is now sprayed airlessly into the exhaust stream via an improved metering unit, and the nitrogen oxides are almost completely converted into water and nitrogen in the SCR catalytic converter.
The exhaust system of the Euro VI engines is also equipped with a highly effective diesel particulate filter, which only requires an initial service at 360 000 km in the Travego, and then every 240 000 km thereafter.
To avoid a high counterpressure in the exhaust system, with corresponding negative effects on fuel consumption, the entire exhaust gas aftertreatment system including the oxidising catalytic converter, particulate filter and SCR catalytic converter is of double-flow design. All the components are installed in a single housing.
Travego Edition 1: lower emissions, low fuel consumption
In practice, the introduction of Euro VI in the Travego Edition 1 means a further drastic reduction in exhaust emissions without the initially feared increase in fuel consumption. At the same time the consumption of AdBlue is around 40 percent less.
To achieve these aims the developers of the Travego Edition 1 had to pull out all the stops. A significantly higher cooling performance is required for Euro VI, for example. This was achieved following extensive calculations and tests: moving the radiator from the left to the right side, isolating the radiator from the engine compartment, additional air vents at the vehicle rear, the use of optimised fans and fan couplings with an improved control range. All in all, the efficiency of the cooling system was improved by 30 percent. In addition it was possible to further reduce noise and engine compartment temperatures.
Euro VI components have no effect on passenger and luggage capacity
The additional components for Euro VI naturally presented further challenges with respect to vehicle weight and weight distribution: vehicles fitted with Euro VI components tend to be "rear-heavy". To achieve an optimal weight distribution, the developers moved the fuel tank in front of the front axle, switching it with the position of the batteries.
At the same time the vehicle weight was reduced further by optimising the standard components (e.g. windows and air conditioning system). This helped to implement a major requirement: buses meeting the Euro VI emission standard must have no restrictions in passenger and luggage capacity compared to the previous Euro V models.
New powertrain subjected to endurance testing
Extensive tests verified the reliability of the new powertrain. Within one year, five long-distance test vehicles together covered more than 1.5 million km. Operating for 20 hours a day and seven days a week, they covered up to 300 000 km within a year. Testing mainly took place in Turkey, under extreme climatic conditions. In the southern regions of Turkey, summer temperatures reach more than 25 degrees Celsius on up to 192 days of the year, with peaks above 45 degrees Celsius. The eastern regions are in stark contrast to this: for half the year it is winter with temperatures below freezing, which can even fall to below minus 40 degrees Celsius.
Buyers of a Travego Edition 1 benefit from numerous advantages: the new-generation BlueEfficiency Power engines are even more durable and robust than their predecessors. 90 percent of these engines are capable of 1.2 million km with no overhaul (preceding series: 1.0 million km). The service intervals of the new engines have also increased to up to 120 000 km (preceding series: up to 90 000 km).
Fuel consumption is low and AdBlue consumption has fallen drastically. With its low exhaust emissions this touring coach is future-proof. The low operating noise means even greater comfort for its passengers.
New GO 250-8 PowerShift transmission
Together with the Euro VI engines, Mercedes-Benz is introducing the new eight-speed GO 250-8 PowerShift bus transmission in the Travego Edition 1. This fully automated transmission is based on the highly popular GO 240-8 PowerShift transmission still in use in other models.
Drivers benefit from the familiar, progressive ratio graduation, together with fast and comfortable gearshifts. The ratio spread likewise ranges from 6.57 in first gear to 0.63 in top gear.
The designation of this transmission indicates that it is approved for a maximum engine torque of 2 500 Nm. A heat exchanger now keeps the oil temperature in the transmission at a constant operating level of around 80 degrees Celsius. This has a positive effect on oil change intervals.
Practical crawler mode and a new retarder
The vehicle also features a new crawler mode which works in the same way as on automatic transmissions. It allows for precise manoeuvring by only using the brake pedal.
The new, integrated retarder achieves a braking torque of up to 3 500 Nm. It is designed as a secondary retarder and uses the engine coolant for braking and cooling. This eliminates the previous oil/water heat exchanger and the associated oil changes for the retarder. Despite the improved performance, this measure has reduced the dry weight of the new GO 250-8 by 20 kg to 285 kg compared to the previous transmission.
The practically wear and maintenance-free clutch is also new. Thanks to a centrically located, pneumatically operated clutch cylinder it dispenses with mechanical parts such as a release fork, release bearing and servo assistance.
Gearshifts now by steering column stalk
The gearshift of the GO 250-8 PowerShift transmission is completely new: the previous joystick in the instrument panel has now been replaced by a stalk on the steering column. This has all the previous functions, but is also very easy and unmistakable in operation.
The stalk allows the selection of driving modes D/N/R, and when required also a change from automatic and manual mode. The driver is able to intervene manually by briefly pulling or nudging the stalk. As usual he controls the retarder by downward movements of the stalk.
Ergonomically optimised cockpit revised down to the last detail
The steering column stalk for gearshifting is one of the most obvious changes in the cockpit, however the developers have also implemented numerous other ideas designed to optimise the ergonomics for the driver: the new control concept “Stacks and Cards” has been introduced in the instrument panel display, for example. Thanks to the use of pictograms and structured menu navigation via the new multifunction steering wheel, it is now very much simpler to navigate through the various functions and displays.
The new electronic key is inserted into the instrument panel on the left side. Control of the ignition and the engine start/stop system is by a two-stage function key. The switches in the cockpit have been rearranged according to their function, and their number has been noticeably reduced by multiple assignment. In the Travego Edition 1 the space formerly occupied by the gearshift joystick is now taken up by an open stowage tray.
Large, easily legible instruments
Another new feature of the display is the use of non-reflecting glass. Two large needle instruments indicate the road speed and engine speed, while two smaller instruments indicate the fuel and AdBlue levels. Using the steering wheel buttons, the driver is able to access a great deal of further information in the central colour display.
On the right side the driver operates the entertainment electronics in the usual way. The console now houses the new Blaupunkt Professional Line 3 radio system including a hands-free function and a USB connection for MP3 formats.
New Attention Assist safety system warns of driver fatigue
It's somewhat of a tradition: with the introduction of every new premium high-deck bus, Mercedes-Benz Travego celebrates the premiere of new safety systems in buses. This is also true in the case of the Travego Edition 1: the new optionally available Attention Assist is unique among buses and will be available from the end of the year.
The system analyses parameters such as the steering angle, speed, longitudinal and lateral acceleration, journey duration, operational signals and driver changes. From the correlation of this data, Attention Assist is able to deduce the driver’s condition. If the data suggests a driver is tired or lacking concentration, a coffee cup is shown in the display to inform the driver to take a break.
New Active Brake Assist 2 brakes if stationary obstacles are detected
A further new development for the Travego is the second generation of Active Brake Assist which is available from the end of the year. The system is now able to detect stationary obstacles. Previously, the system was only able to initiate emergency braking manoeuvres if the risk of a collision with a slower moving vehicle ahead was detected. Active Brake Assist 2, however, can also initiate emergency braking in the case of stationary obstacles, such as for example an unexpected traffic jam on the motorway.
The radar-based system scans an area between 0.25 and 200 m of the lane in which the vehicle is currently driving and then continually calculates the distance to a vehicle driving ahead, as well as the difference in speed between the two vehicles; in the case of an obstacle, it calculates the distance to the obstacle. The radar technology works reliably in almost all weather and light conditions. Active Brake Assist is active in the entire speed range from manoeuvring speeds right up to 100 km/h.
As ever, Mercedes-Benz is supporting the distribution of the life-saving system Active Brake Assist: the system will be delivered free of charge in conjunction with the optionally available adaptive cruise control.
New: LED daytime running lamps and tyre pressure monitoring
Further equipment increases the safety of our vehicles. LED daytime running lamps integrated into the housing of the headlamps are optionally available. Equally available as an optional extra, the tyre pressure monitoring system displays the current tyre pressure in each tyre and warns the driver if this changes from the optimal tyre pressure. This reduces wear on the tyres, has a positive effect on fuel consumption and helps avoid potentially dangerous tyre damage.
The discreetly integrated daytime running lamps and the ventilation grilles in the engine compartment cover, as well as the moving of the ventilation grilles from the left to the right-hand side are the most visible changes to the Travego Edition 1. More observant followers will also note the change of the fuel filler flap to its new position in front of the front axle.
Travego Edition 1 series start has begun
The introduction of the new Travego Edition 1 will start with the triple axled Travego L and Travego M with 14 and 13 m length respectively. As stated at the premiere of the Kortrijk bus exhibition last year, vehicle delivery has already begun: at the end of March, the first Travego Edition 1 was delivered to a Sweedish company.