This sort of photos is quickly becoming a tradition for Mercedes-Benz in advance of the official presentation of a new model. After the SLS and the SLK got previewed in the same way, it's time we saw a bit of the upcoming B-Class. And that's exactly what happened a few days ago when a set of teasers and technical images were leaked onto the web. Among the photos we found two darkened studio shots which only reveal the basic shape of the new compact MPV. The rest showcase either the construction of the body structure, made up of various materials divided into specific panels, or certain components such as the steering column or the front axle. One photo reveals the multitude of safety and assistance systems the new B-Class will feature: Collision Prevention Assist, DISTRONIC PLUS, Speed Limit Assist, Adaptive Highbeam Assist, ATTENTION ASSIST, Lane Keeping Assist, Blind Spot Assist, PRE-SAFE, Active Parking Assist, Torque Vectoring Brake, a rich list of airbags (thorax, pelvis and kneebags in addition to the conventional ones) and many other clever solutions to make your life easier whilst driving.
Photo Source: Mercedes Fans
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It’s the beginning of July and we’re just a few days off heading to our home race – the Santander British Grand Prix. There’s much to look forward to, with a new pit and paddock complex and a new starting position for our drivers Lewis Hamilton and Jenson Button.
Lewis has fond memories of racing at Silverstone – he won the race the year he won his World Drivers’ Championship and is looking to add another home win to his tally if possible.
He said: “My victory at Silverstone in 2008 was one of the sweetest and most satisfying moments of my entire Formula 1 career – and it’s a memory that I always carry with me. Standing on the top step of the podium, and looking across at the sea of flags and faces in the grandstands opposite was simply incredible.
“For this year, of course, we head to a very new Silverstone – and while much has changed around the circuit and in the paddock, I’m sure that all those thousands of fans will be just as passionate as ever – it’s one of the greatest things about the Santander British Grand Prix.
“Going into this race, we’re facing some very stiff new interpretations of the regulations; while they’ll affect all teams, it will be interesting to see if the competitive order is changed as a result. It’s going to be a busy weekend for our engineers as they adapt – as always, they’ll do a fantastic job to ensure we stay competitive.
“I’m really looking forward to Silverstone: it’s one of the best circuits in the world, and I really think that the arrival of DRS and KERS Hybrid will make this one of the best and most exciting British Grands Prix ever.”
Jenson is eager to improve on his career best fourth place finish at the circuit and admits it would mean everything to win in front of his home fans, which in his eyes are some of the greatest in the world.
He said: “My best finish at Silverstone is fourth, which I earned in 2004 and last year, after a great charge through the field after a disappointing performance in qualifying. Although it’s a place that’s not been too kind to me, I’m really looking forward to this year’s race: we raced on the new layout last year, but this will be the first time we’ve experienced the new circuit as it’s really meant to be.
“With a new startline, a new first corner and an all-new pit and paddock complex, the new facilities should be fantastic, and I think they’ll confirm Silverstone as one of the best circuits in the world. Still, it’s going to be strange sitting on the grid with the prospect of going flat into Abbey as the first corner!
“As always, we’ll see once again that the British fans are some of the most passionate, knowledgeable and loyal in the whole world. It would mean everything to me to be able to win my home grand prix – that would be my dream come true. Whatever happens, it will be a great weekend.”
Martin Whitmarsh believes the recently constructed new pit and paddock complex at the circuit will help cement Silverstone’s place as the home of British motor racing. He’s also keen to see if mid-season rule changes will shake up the competitive order.
He said: “This will be an exciting time for teams and fans alike as we head to an all-new Silverstone for the Santander British Grand Prix. Silverstone has been the spiritual home of Formula 1 in Great Britain since the birth of the world championship back in 1950, and it’s hugely rewarding to see that, not only has the circuit gone from strength to strength, but that it’s still leading the way.
“The new track layout, which we raced for the first time last year, and the superb new pit and paddock facilities, will confirm Silverstone as one of the greatest racetracks in the world and cement it as the home of British motor racing.
“This weekend will also be exciting for different reasons, with new restrictions placed on off-throttle exhaust blowing and the anticipated effect that may have on the competitive order. As always, our engineers have been committed and resourceful in managing this mid-season change, and I’m optimistic that we’ll remain competitive and will hopefully be able to provide the many thousands of home fans with a good result next weekend.
“It’s important that grand prix racing continues to change while simultaneously respecting its past: I think the advent of a new rules package at Formula 1’s spiritual home is the perfect reflection of a sport that has managed to capture and thrill generations throughout the ages.
“As our home race, I sincerely hope this will be a great Santander British Grand Prix!”
* Official photo and details courtesy of VODAFONE MCLAREN MERCEDES *
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
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Like every daring project, it all began with a blank sheet of papers. After a long period of in-house development, the new Actros eventually had to taste tarmac for the first time. Prototypes "dressed" in deep black "clothes" started rolling out of the Mercedes-Benz truck R&D centres onto the streets of the world. Around 20 million miles were covered during the testing phase, going from the hot South Africa up to the freezing-cold Arctic Circle, to demonstrate the new Actros is ready to successfully handle extreme weather conditions. The truck also showed an outstanding reliability, suffering no overhaul in 1.2 million kilometres of intensive run. Last, but not least, the engine has undergone over 60 million kilometres of thorough testing.
No other truck has been as thoroughly developed and tested before its production launch as the new Mercedes-Benz Actros. The foundations for development were laid as many as ten years ago, while the components and the complete vehicle have undergone five years of testing. During this time, the new Actros has clocked up around 20 million miles on the road, including in intensive customer driving tests. Then there were the extremely rigorous tests on test rigs, torture-track testing and other extreme examinations.
It all began on a blank sheet of paper
The story of the new Actros really did begin on a blank sheet of paper. To come up with a successor to the successful outgoing model, designers, developers, marketing specialists, product managers and everyone else involved started from scratch. Rather than make the new Actros a further development of its popular, tried-and-trusted predecessor, the aim was to start afresh so as to come up with a perfect and future-proof solution for operators and drivers. No stone was therefore left unturned during development.
The cab comfort features were redefined and redesigned, and the cabs themselves were dimensioned accordingly.
This approach gave rise to an all-new range structure: instead of two model series with their own characteristics for long-distance transport, short-distance transport and construction work, there are now three model series, each one specialising in one of the above disciplines. The first member of the new, three-strong family of Mercedes-Benz heavy-duty trucks is the new Actros, which exclusively covers the long-distance-transport segment in all its guises. The other members of this family will follow.
New range structure with the focus on long-distance transport
Focussing on the new Actros as a premium truck for long-distance transport opened up many new possibilities. For the first time, both the inside and outside of the cab were designed specifically for a single field of application. Development was based on several 1:4 scale models, which allowed the designers great freedom in determining the direction the new Actros would take.
From these, six 1:1 scale models were derived – three for the exterior and three for the interior. Even the very first interior sketch defined the clear visual distinction between the working and living areas – a first in truck development.
Some 1600 Daimler Trucks staff worked on the new Actros, including vehicle developers, testers and the major-component developers concerned. Their work was frequently monitored by the testing department as well as in special Truck Clinics. In four of these Clinics, a total of 638 operators and drivers were interviewed at great length.
Long before production started, the new Actros experienced the Arctic Circle in winter and the searing heat of Spain's Sierra Nevada in summer. It negotiated all kinds of roads in Turkey and got a taste of desert sand in South Africa.
Engine has undergone over 60 million kilometres of intensive testing
The launch of the new Actros also marks the introduction of a new generation of six-cylinder in-line engines. The outstanding quality of the new engine generation was evident even during its development. Extreme reliability and durability were among the most important development objectives. In order to achieve this, the engines were tested under the toughest of conditions, all over the world. To date, the engines have clocked up in excess of 60 million kilometres in endurance testing on test rigs and in real-life operation, for all emissions classes. No engine ever before has been as intensively tested.
Tested under the toughest of conditions, from the Arctic Circle to South Africa
The real-life road tests also covered all climatic conditions as well as extreme road conditions and gradients, ranging from an Arctic winter to an extremely hot desert climate. Real-life testing also included customer driving tests in the previous Mercedes-Benz Actros.
Outstanding reliability: 1.2 million kilometres without overhaul
On top of all this came customer driving tests of a very special nature, from
Mercedes-Benz's point of view: in North America and Japan, more than 70,000 engines are now working successfully in Freightliner and Fuso heavy-duty trucks. New-generation engines – albeit in a special configuration for the respective region – have already been in daily customer use there since 2007 (North America) and 2010 (Japan).
The findings from the tests conducted under extreme conditions have proved very positive. For instance, the new engine series achieves a "B-10" figure of 1.2 million kilometres, i.e. 20 percent higher than previously, in European long-distance transport. This means that the engines can cover at least this distance without the need for a major overhaul.
Source: Daimler AG
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A tough truck wouldn't be complete without brilliant underpinnings. The new Actros is equipped with a dynamic chassis based on a torsionally stiff frame with wide track. It integrates an intelligent concept which improves ride comfort and helps for a sensitive and firm steering for added fuel economy. The assistance systems provide extra safety and relieve stress when the truck is stuck in traffic. In the future, the range will be extended as the chassis was developed to properly fit new and additional wheelbase lengths.
Criteria such as handling and safety are becoming increasingly important in long-distance transport. The new Mercedes-Benz Actros takes account of this, ushering in a new era of driving dynamics for heavy-duty trucks. No other premium-category truck feels as poised, assured or safe on the road, largely thanks to a new frame and an extensively modified chassis. The new truck's exemplary ride comfort is at the same high level. A Mercedes-Benz is always extremely well prepared should the worst come to the worst: the already outstanding safety level has been further enhanced by extended functions. Last but not least, a perfected modular system means that the new Actros is available with a wide choice of wheelbase and frame variants. Plus it offers exceptional body-mounting ability.
Complete chassis and ride-comfort concept
Major plus points of the new Actros include its driving dynamics, handling and comfort, largely thanks to a complete chassis and ride-comfort concept, from the frame and the chassis through to the cab suspension and the driver's seat. A wealth of innovations in this field means that the new Actros conveys a safer driving feel than any other truck in its class.
Torsionally stiff frame with wide track
A new frame, uncompromisingly designed for on-road vehicles, forms the backbone of the new Actros. It is exceptionally torsionally stiff and has a wide track of 834 mm (previously 744 mm). Both factors together form the basis for excellent handling stability – the Actros hugs the road with an assured feel.
Tried-and-tested axles and a dynamic, new chassis
The core design of the tried-and-tested axles is the same as for the predecessor model; however, the developers have completely redesigned the control and the suspension to enhance driving safety and ride comfort.
New features include the location system for the Mercedes-Benz HL6 hypoid rear axle, based on optimised rear-axle location with new geometry and lines of action that now intersect behind the axle. Four-bellows air suspension, which responds precisely to road unevenness, is now responsible for the ride comfort. This is a symmetrical air suspension system (i.e. the bellows are of the same size). The spring track is wider than previously. Another advantage is the fact that four bellows operate faster and can lift higher loads than two bellows.
The tried-and-tested offset front axles are available with either steel or air suspension and with a choice of tonnages. The number of spring layers varies depending on the permissible axle load. The weight of the steel springs has been reduced thanks to an aluminium front spring bracket. New features include weight-optimised suspension with single-leaf parabolic springs on the front axle.
The chassis for the new Actros impresses with its high levels of directional stability, outstanding understeer/oversteer characteristics and high precision. Ride comfort has also been further enhanced.
Three cab mounting variants
The cab mounting is a major component in the driving-dynamics concept. There is a choice of three variants for the new Actros: Standard cab mounting, Comfort cab mounting (standard for cabs with a flat floor) and the exceptionally comfortable air suspension.
Sensitive and firm steering even saves fuel
One of the key factors behind the new Actros' excellent handling is the steering system, which impresses on account of its precision, thanks to a re-tuned steering gear, and conveys excellent road feel. The ratio is more direct whilst the kinematics have been improved and the controlled power steering pump saves fuel.
Powerful new engine brake and highly effective retarder
In 1996, the forerunner to the new Actros revolutionised the truck world on account of its four-disc brake system with a high-pressure system and electronic control. The new Actros takes this exceptional brake system a stage further. A new, optionally available high-performance engine brake sets new standards once again. The three-stage engine brake achieves an immense braking power of up to 400 kW (544 hp) on Euro VI models. Another new feature is the optionally available water secondary retarder with a braking torque of up to 3500 Nm or up to 750 kW. As well as being more powerful, the new retarder is lighter, weighing in at just 65 kg instead of 100 kg as previously.
Assistance systems to enhance comfort and relieve stress when stuck in traffic
The previous model series also set milestones with its safety and assistance systems. Whether it be adaptive cruise control, Lane Keeping Assist, Stability Control Assist or the revolutionary Active Brake Assist with autonomous emergency braking when stationary obstacles or moving obstacles ahead are detected, the Actros has always led the way for others to follow.
The new Actros builds on this lead. Stability Control Assist is now fitted as standard on both the semitrailer tractor and the chassis version, while the unique Proximity Control Assist system with stop-and-go function now even controls moving off and stopping in traffic automatically – making the driver's job much easier when driving through cities or in stop-and-go traffic. What's more, the Proximity Control Assist is no longer automatically linked to the retarder. The sensed fifth wheel coupling informs the driver of its lock status via a display in the cab. The exterior mirror with manoeuvring function on the co-driver's side extends the range of vision when manoeuvring by automatically adjusting outwards by ten degrees when reverse gear is engaged.
Standard equipment for all Actros models includes automatic activation of the hazard warning lights following an emergency stop so as to warn following traffic and help prevent rear-end collisions. The optional rain and light sensor activates the windscreen wipers and dipped beam when required, while the likewise optionally available tyre pressure monitoring system for the tractor and trailer is primarily aimed at enhancing safety: burst tyres as a result of insufficient inflation pressure are just as much of a safety risk as flat tyres. Furthermore, insufficient tyre inflation pressure increases the tyre's flex and, therefore, fuel consumption as well as reducing service life – a key factor when it comes to economy.
Attractively priced safety packages
Ready-made safety packages available at attractive prices encourage the inclusion of safety technology. The “Basic Safety Pack” comprises Proximity Control Assist, Lane Keeping Assist and a driver's airbag, while the Classic Safety Pack includes all of these as well as Active Brake Assist and roll control for dropsiders. Meanwhile, the Top Safety Pack features all of the above plus a retarder.
Range extended to include new and additional wheelbase lengths
The new Actros is a bespoke premium truck with an even larger range of models available than its predecessor. It can be ordered as a two- or three-axle version with trailing or leading axle and with a choice of three frame heights: standard, low and lowliner. Mercedes‑Benz has also further extended the range of wheelbase lengths by narrowing the gap between each version. Hence the two-axle semitrailer tractor is now available with a choice of four wheelbase lengths – 3550, 3700, 3850 or 4000 mm – while the two-axle chassis with cab gives customers a whopping eleven wheelbase lengths to choose from, ranging from 3600 to 6600 mm in steps of 300 mm.
Low-frame and lowliner models now have a slightly lower coupling point height, while the dropsider frame is also noticeably lower, making it easier to mount bodies.
Good body-mounting ability prioritised
The new Actros chassis already offers exceptionally good body-mounting ability as it is. The 50 mm hole pattern throughout in the frame side members, including the area of the axles, gives bodybuilders a great deal of freedom, as does the absence of rivets aft of the rear axle. Frame overhangs can be selected in steps of 300 mm, while the end crossmember can be relocated in 50 mm steps.
Although the exhaust system takes up more space on the frame due to the Euro VI requirements, optimised exhaust outlets make the bodybuilder's job easier. If required, space can be left within the frame – for demountable-platform vehicles, for example. In this case, there is no need to relocate the tank subsequently. Standardised fastenings, brackets and fixing bolts facilitate body mounting. All of which saves costs and shortens delivery times.
New chassis with new tanks
The wider frame, the in-line engines and the more complex exhaust gas aftertreatment system for Euro VI require a modified chassis design. The developers have taken this opportunity to introduce a new fuel tank concept among other things. Four tank cross-sections give a fuel supply volume of 290 to 1300 litres. The tanks are flexibly inter-combinable for individual solutions, and there are no conversion costs. Even the AdBlue tanks are available in a choice of sizes: 60 or 75 litres.
The main fuel tank and the AdBlue tank are mounted on the left-hand side of the vehicle. There is space for an additional tank on the right-hand side. The full vehicle width of 2.55 metres can be used to optimise the tank volume. There is also a combination tank with two chambers for diesel fuel and AdBlue available for semitrailer tractors.
Source: Daimler AG
Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.
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The new Mercedes-Benz Actros is the very first truck to receive the newly-premiered Blue Efficiency Power units that fully comply with the stringent Euro VI emission standard. These diesel engines boast excellent technical characteristics, low fuel consumption, exemplary robustness and longevity and provide high levels of output and torque across a wide range of rpm. Engineers have also mastered the X-PULSE, a new commonrail system with pressure booster, and a powerful and dynamic three-stage engine brake. Furthermore, the new powerplants feature efficient emission control solutions: the SCR technology, exhaust gas recirculation and the particulate filter. Power is sent to wheels thanks to the introduction of the third generation of Mercedes-Benz PowerShift fully-automated transmissions, tweaked for faster and more effective gear shifts.
The launch of the new Mercedes-Benz Actros heralds the arrival of a completely redesigned range of heavy-duty engines which set new standards in many respects. The new Mercedes-Benz BlueEfficiency Power engine generation has been developed specifically for use in Europe and, from the outset, will meet Euro VI requirements. The first member of the new engine family to be in the spotlight is the Mercedes-Benz OM 471 six-cylinder in-line unit, with an output range that covers the bulk of European long-distance-transport requirements. The OM 471 counters the unavoidable extra expense for Euro VI by incorporating state-of-the-art technology. As a result, the new Actros is not only cleaner, it also consumes far less diesel than its predecessor.
New engine already meets the requirements of the forthcoming Euro VI emissions standard
With this new engine generation, Mercedes-Benz continues its tradition as a trailblazer in terms of environmental compatibility. The OM 471 is the first engine in its class to be homologated in accordance with the future Euro VI emissions standard, so marking the start of a new era a full two years before Euro VI actually becomes law. Euro VI brings further significant reductions in, above all, nitrogen oxides and particulates in the exhaust gas.
The new Mercedes-Benz OM 471 covers an output range of 310 kW (421 hp) to 375 kW (510 hp), with peak torques between 2100 and 2500 Nm. During development of the OM 471, the Mercedes-Benz engineers were able to call upon a wealth of experience: the core design of the engine is based on the new platform used for Daimler Trucks' heavy-duty engines. These have been used very successfully since 2007 in trucks produced by Daimler's North American Freightliner brand (built by company-owned engine manufacturer Detroit Diesel) and since last year by Fuso in Japan.
BlueEfficiency Power: top class from Mercedes-Benz
Operators as well as drivers of the new Actros want powerful engines with good traction and low fuel consumption, along with high overall economic efficiency. They expect the best possible performance as well as refined, quiet running and exhaust gases that are low in pollutants. The new engine generation meets these requirements thanks to its robust construction and high-grade engineering, including four valves per cylinder, two overhead camshafts and a fully electronically controlled injection system with pressure booster that is unique in the world.
Like the Actros itself, the new Mercedes-Benz engines are top class in every respect. Top class in terms of the outstanding and innovative engine technology with exceptional economy and refinement thanks to the new, unique X-PULSE injection system. Top class in terms of excellent engine dynamics thanks to turbocharger technology. Top class in terms of low emissions thanks to the combination of SCR technology, exhaust gas recirculation and a particulate filter. And top class in terms of the powerful, new engine brake. Not to mention the new engines' serviceability and durability.
A wealth of output and torque variants
The Mercedes-Benz OM 471 is available with a choice of four outputs and torques for the new Actros. These configurations are suitable for typical European application conditions and meet operators' and drivers' requirements. The following versions of the Mercedes-Benz OM 471 are available for the new Actros:
Output (kW) - Output (hp) - Torque (Nm)
310 - 421 - 2100
330 - 449 - 2200
350 - 476 - 2300
375 - 510 - 2500
One of the particular highlights of the new OM 471 is the fact that, if the standard rear-axle ratio of 2.611 is specified, 200 Nm of extra torque are provided when the automated transmission is in top gear so as to prevent downshifts when driving uphill.
BlueEfficiency Power: high torque even below 1000 rpm
The rated engine speed of the new engines is set at 1800 rpm for all output variants, with the maximum torque available at just 1100 rpm. But these figures can only be a guide: as a result of the very steep output curve immediately before the main operating range, most of this maximum torque is already available at an engine speed of just 1000 rpm. Even below 1000 rpm, the torque is surprisingly high. This results in an extension of the usable engine speed range at the bottom end – down to around 800 to 900 rpm, depending on the route profile – with a correspondingly positive effect on fuel consumption.
Excellent driveability: high output across a wide rpm range
The same is true of the output curve: even at 1400 rpm, the engines deliver almost 100 percent of their full output. In reality, on the road, the output and torque curves combine to ensure excellent driveability with a high output in all key engine speed ranges. The Mercedes-Benz OM 471 reinforces this sense of dynamism with its quiet, smooth running, which is nevertheless characterised by the brand's hallmark sonorous and distinctive sound.
Compact six-cylinder in-line engine
The design of the new Mercedes-Benz OM 471 is based on six cylinders mounted vertically in-line – a platform that bodes well for the smooth running of the engine. The long-stroke design of the Mercedes-Benz OM 471, which has a bore of 132 mm and stroke of 156 mm, gives it excellent pulling power. The engine is categorised in the heavy-duty class for heavy-duty commercial vehicles. The dry weight of the Euro VI version is 1146 kg, while the weight to DIN 70020-A is 1126 kg.
Exemplary robustness and longevity
In order to meet the demands made of the new Actros class of high-powered heavy-duty trucks, exceptional robustness and durability are among the outstanding characteristics of the engine. The crankcase, for example, is made of a grey-cast-iron material developed and patented specifically for this engine generation and includes vertical structures and ribbing to make it very rigid. This design also reduces noise emissions.
The single-piece pistons, made from steel to maximise their service life, each feature two compression rings, an oil control ring and splash-oil cooling. A protective coating ensures that the engine will perform under load, even while it is being run-in. The almost negligible distortion of the pistons and the rigid crankcase keep oil consumption and blow-by losses to a minimum – so reducing costs and improving environmental acceptability. The fine plateau honing of the cylinder liners likewise reduces oil consumption as well as friction losses.
Optimum engine cooling is ensured by wet cylinder liners. The main cooling flow circulates around the upper third of the liner, while a secondary flow cools the lower section, which is not subject to such high temperatures. In general, the distances travelled by the coolant are kept short, making the cooling process here very efficient. The cooling thermostat is located at the intake end to ensure precise control. Larger radiators with a higher output reduce the thermal load whilst the fan does not have to operate as frequently, thus reducing fuel consumption.
Smooth running and an extremely rigid design
The "cracked" connecting rods are split at the connecting rod eye. In this process, the connecting rods are broken at a defined point, producing an extremely robust, close-fitting join with a large surface area when they are screwed back together. A precisely balanced seven-bearing crankshaft ensures exceptionally smooth running of the engine.
The highly rigid crankcase, steel pistons, and reinforced connecting rods and bearings were selected with the high engine ignition pressures in mind. To maximise efficiency, these have been increased from their previous level of 180 bar to over 200 bar.
The turbocharger, starter motor and crankcase ventilation system are all located on the hot side of the engine, while the engine control unit, the oil coolant module with filter and coolant pump, the fuel pumps for the high- and low-pressure system, and the consumption-optimised two-cylinder air compressor with on-demand control are grouped together on the cold side of the engine for ease of maintenance.
Exceptionally robust cast-iron cylinder head
The one-piece cylinder head for the new engine is made of grey cast iron with vermicular graphite (also known as CGI). It is exceptionally robust and designed for the high ignition pressures in the new engines.
Efficient gear drive, double overhead camshafts
At the front end of the engine, poly-V-belts drive the alternator, the coolant pump, the refrigerant compressor and the fan. The now closed-loop coolant pump is only activated as and when needed so as to reduce fuel consumption.
The extremely compact and rigid gear drive is located at the engine's output end, where it operates exceptionally efficiently, quietly and smoothly. Each of the camshafts controls two intake and exhaust valves arranged vertically in the cylinder head via low-friction rocker arms mounted in friction bearings. Rather than being milled from a solid piece of material, the camshafts are of "composite" or "assembled" design – a premiere for engines of this size – and are based on a hollow construction to save weight. They are mounted in a die-cast aluminium camshaft frame with seven bearings.
X-PULSE: unique common-rail system with pressure booster
One of the key aspects of the new engine generation for the new Actros is clean and efficient fuel combustion based on a flexible, fully electronically controlled common-rail system. Flexible in this case means that not only can the injection pressure, timing and quantity of fuel injected be varied, but also the injection rate, thanks to the new X-PULSE injection system with pressure booster that has been developed exclusively with Daimler Trucks.
Maximum injection pressure of 2100 bar
In the X-PULSE common-rail system with pressure booster, the twin-piston high-pressure pump produces a maximum pressure of around 900 bar in the common rail. This pressure is then boosted to up to 2100 bar in the individual injectors. The X-PULSE pressure booster can be varied on the engine map and adjusts continuously to the current engine operating conditions – for example to the demand for torque from the accelerator pedal. The engine control unit manages the injection point, injection quantity, injection rate, number of injections and injection pressure separately for each injector, enabling it to even out any differences between the various cylinders.
Pilot, main and post injections
X-PULSE allows an exceptionally high maximum injection pressure to be achieved as well as enabling free adjustment of the pressure and pressure distribution during main injection by means of two solenoid valves. As all the parameters are variable, each individual injection can be precisely adjusted to the specific situation.
Smooth running, economical, clean: main injection rate can be freely shaped
Many different forms of injection are possible with the new X-PULSE injection system. Their use depends on various parameters, such as the engine load: injection without pressure boosting but with just the pressure in the rail, injection with very early pressure boosting ("square" injection rate) or injection with late pressure boosting ("boot" rate). A variant in between ("ramp" rate) is also possible.
All in all, this means that for the first time it is possible to control fully the injection sequence at each engine operating point. As the highest pressure is only produced actually inside the injectors, the injections are exceptionally stable. In the case of the new Mercedes‑Benz engine generation, this results in quiet and smooth running with a high level of refinement, extremely low fuel consumption and minimal exhaust emissions.
Swirl-free turbulence, efficient combustion
The injection process takes place in a geometrically optimised combustion chamber with a shallow piston recess. The X-PULSE injector is positioned vertically and centrally between the vertically arranged intake and exhaust valves. It features an injection nozzle with seven injection orifices designed as miniature blind-orifice nozzles. The high maximum injection pressure and extremely fine fuel atomisation in the combustion chamber are the keys to efficient combustion. The combustion chamber is shaped to prevent swirl and tumble and to make the combustion of the fuel/air mixture as efficient as possible. The engines' relatively high compression ratio of 17:1 is also aimed at maximising economy.
Asymmetric exhaust gas turbocharger
The new Mercedes-Benz OM 471 has a turbocharger with an asymmetric turbine housing and fixed geometry as well as an intercooler. The asymmetric flow is an advantage, as the exhaust gases from the first three cylinders go directly through the exhaust gas recirculation system to the turbine without any losses. This process improves engine response.
Powerful and dynamic three-stage engine brake
Superb efficiency is one of the key characteristics of the new Mercedes-Benz OM 471, and this is also true of the engine brake. Mercedes-Benz uses a turbocharged decompression brake, which operates extremely effectively and quietly. The fast response time of less than 150 milliseconds is also remarkable.
The engine brake is controlled in three stages through the steering column stalk. In the first stage, the engine brake is activated on three of the cylinders. The remaining three cylinders are then activated in a second stage. In the third and highest stage, the EGR valve and wastegate are activated to increase the engine's charging level and so achieve the maximum brake power of 2300 rpm at 400 kW (544 hp). In addition to this manual actuation, the engine brake is also used in cruise control mode.
Motor control module MCM: everything under control
As the engine's "brain", the MCM (motor control module) is not only responsible for translating the demand for power governed by the driver's foot on the accelerator, but also for controlling and monitoring all the engine functions, from the start and rate of injection through to actuation of the engine brake.
By way of example: in order to achieve perfect synchronisation during gear changes, the engine needs to reach the requisite nominal speed as quickly as possible. To do so, it is even possible to fire individual cylinders whilst other cylinders are being decelerated by the engine brake. Very fast and smooth gear changes are therefore possible.
The control module uses sensors to constantly check factors such as oil level, the position of crankshaft and camshafts, the pressure in the common-rail system and the injectors, the turbocharger turbine speed, the temperature of the engine oil, coolant, fuel and charge air, the charge pressure, and the exhaust gas recirculation rate. As a result of this extensive monitoring, the engine always operates in its optimum range – the prerequisite for good performance, low fuel consumption, a long service life and low exhaust gas emissions.
Efficient emission control: SCR technology, exhaust gas recirculation, particulate filter
Conscious of the stringent requirements imposed by the Euro VI emissions standard, Mercedes-Benz has developed a combination of SCR technology with AdBlue insertion, cooled exhaust gas recirculation (EGR) and a particulate filter for the new BlueEfficiency Power engine generation in the new Actros. This solution has already proved successful on the road in commercial vehicles from Daimler Trucks on other continents. However, the configuration here is adapted specifically to comply with European emissions legislation, while the particulate filter, including its regeneration strategy, is also a special European development. All of the systems combine to ensure extremely efficient emission control.
The differences between the optionally available Euro V versions and the standard Euro VI variant include the omission of the particulate filter, a reduced recirculation rate in the EGR system and a smaller EGR cooler. To meet customer demand, there are also EEV variants in the line-up. These are based on the Euro V version. EEV and Euro V versions are available with a choice of three power outputs: 310 kW (421 hp), 330 kW (449 hp) or 375 kW (510 hp).
Low fuel consumption despite Euro VI: a milestone in engine development
Along with a high level of environmental compatibility, one of the key aims during the development of the new engine generation was to minimise lifecycle costs. First of all, this involves low fuel consumption. Despite the added complexity that was necessary to meet the requirements of the Euro VI emissions standard, these versions of the Mercedes-Benz OM 471 boast exceptionally low fuel consumption and achieve record figures in all versions of the new Actros. AdBlue consumption is also reduced drastically in the Euro VI versions.
The Euro V version of the OM 471 has even lower fuel consumption. It has a lower exhaust gas recirculation rate and dispenses with the particulate filter.
Exceptionally long service intervals ensure low lifecycle costs
At the same time, the developers have been concentrating on keeping maintenance costs down. The service intervals have now been extended to up to 150,000 kilometres, the precise figure depending on the vehicle type and its usage profile. This interval is an exceptionally good figure for an engine with exhaust gas recirculation. In reality, this means the new Actros models in many long-distance transport fleets will require just one annual maintenance call with an engine oil change. The generally maintenance-free particulate filter in the new Euro VI Actros only needs to be changed after 450,000 km and subsequently cleaned after every 300,000 km. The service interval for the air filter in the new Actros is likewise 300,000 km.
The excellent serviceability of the new engine generation also helps to reduce operating costs. A filter module fitted to the cold side of the engine includes the oil filter as well as the filter module for the fuel supply, itself comprising prefilter, main filter and the water separator for the fuel system, grouped closely together in an easily accessible position. The oil refill point is also accessibly located on the cylinder head cover – although the low oil consumption of these engines means that, in reality, the oil will only rarely need refilling.
Mercedes PowerShift fully-automated transmission
In all versions of the new Actros, the power is sent to the wheels through a Mercedes-Benz PowerShift G211 or G281 fully-automated transmission. These transmissions have already proven successful in the predecessor models. And they now offer even faster and more precise response thanks to their highly sensitive shift sensors. The ratios of the twelve-speed transmissions have been optimised for the new engines, the direct ratio in top gear serving as a basis for highly economical long-distance driving. As was the case with the predecessor, application-oriented extra functions such as EcoRoll mode, rocking mode and power mode make the driver's job easier.
New functions for transmission individualisation
New features include a crawler function in place of the previous manoeuvring mode. As in a passenger car with an automatic transmission, the clutch closes when the brake pedal is released. So the new Actros can now be driven at walking pace with a gear engaged but without the need to press the accelerator – making the driver's job even easier when stuck in traffic or when manoeuvring.
Likewise new is the range of freely selectable application-oriented drive programs. The Economy Drive package, installed as standard, offers the driver the already economical Standard drive program as well as an Economy program for significantly reducing fuel consumption on the road. The Economy program does not use kickdown, while the EcoRoll function cannot be deactivated, and the top speed is limited to 85 km/h. The optional Power Drive package includes the fuel-saving Standard program as well as a Power shift program which offers the driver optimum performance. Furthermore, this program allows a GCW of up to 120 t in heavy-duty applications. These individualised shift programs mean that the Actros can be ideally adapted to the particular application conditions.
Faster gear change, controlled by the steering column stalk
Another factor behind the top performance achieved by the new Actros is even faster gear changes with less loss of road speed, which has a positive effect on both average road speed and fuel consumption.
The transmission controls are also new: as every new Actros is supplied with a fully-automated transmission, a steering column stalk is now provided – for the rare occasions on which the driver has to intervene manually.
Tried-and-tested axles, longer ratios
The new Actros is available exclusively with fuel-saving hypoid axles. Although the tried-and-tested HL6 axle from the predecessor has been retained, it now has a new hypoid gear to reduce friction losses. This improvement in efficiency is reflected in lower fuel consumption.
The new high-torque engines with a far wider usable speed range and the "Top-Torque" torque increase in top gear combined with the optimised Mercedes PowerShift with shorter shift times allow a longer rear axle ratio to be used. The standard ratio for semitrailer tractors is now i=2.611 rather than i= 2.846 with a correspondingly lower engine speed level. At a speed of 85 km/h in twelfth gear, the engine in the new Actros runs at just 1260 rpm rather than 1370 rpm – another factor behind the lower fuel consumption achieved by the new Actros.
Furthermore, Mercedes-Benz has extended the range of available rear axle ratios once more. There are now five versions of the HL6 rear axle available for semitrailer tractors with a standard frame height and 315/70 R 22.5 tyres, ranging from i=2.533 to i=3.077. There are also five versions available for lowliner versions with 295/55 R 22.5 tyres, ranging from i=2.2278 to i=2.733.
Economy Packs: economical miracles in package form
If a fleet's main priority is maximum economy, Mercedes-Benz makes it easier to select the right components by offering ready-made Economy Packs at attractive prices. The Classic Economy Pack includes a tyre pressure monitoring system, wind deflectors and side panelling, while the Top Economy Pack also includes a retarder.
FleetBoard and service contracts further boost cost-effectiveness
It's not just the vehicle technology in the new Actros that boosts cost-effectiveness, telematic systems do their bit, too: FleetBoard is included as standard for the first time. The FleetBoard vehicle computer is fitted as standard on board every new Actros. The extensive FleetBoard services can be used free of charge for the first four months. Only after this period does a fee become payable, should the customer decide to continue using FleetBoard. FleetBoard services include trip recording, driving analysis, telediagnosis and maintenance management. What's more, the driver – and only the driver – receives short-time analyses of his or her driving style from the trip computer on the instrument panel display as part of FleetBoard EcoSupport. FleetBoard makes it possible to cut costs by five to 15 percent.
Customised service contracts likewise help to boost the cost-effectiveness of the new Actros. Given the longer service intervals, these are notably less expensive.
Source: Daimler AG
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