New Engines for the New Mercedes-Benz S-Class

Press Release

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The engines in the new S-Class: Strong performance

• New V6/V8 engines and an even more powerful V12

• Up to 26 percent more output and 15 percent more torque

• New V8 engine with 285 kW/388 hp and high-tech features

• Six-cylinder diesel with latest-generation common-rail technology

The engine is the heart of a car. And to make sure that this heart beats strongly over a long working life, the engineers at Mercedes gave it their particular attention during the development of the new S-Class: all the engines in the Mercedes flagship series are new or further developments. They develop more output and torque than the engines in the preceding series, operate even more smoothly and meet the most stringent worldwide exhaust emission standards.

In other words: whatever the choice of engine to power the new S-Class, its heart will certainly be strong and healthy.

The range of petrol engines comprises three power units with six, eight and twelve cylinders. At the lower end of this range is the new V6 engine with 200 kW/272 hp, which Mercedes-Benz has also offered in other car model series for a number of months. The message of this up-to-date six-cylinder unit is: more power, yet lower fuel consumption. Compared to the previous V6 in the S-Class, the new engine develops around eleven percent more output (up 20 kW/27 hp) and consumes nine percent less fuel in the NEDC test (down 1.0 l/100 km/h).

In addition to the latest 24-valve technology and four variable camshafts, this is considerably aided by the unique 7G-TRONIC seven-speed automatic transmission, which is standard equipment in the V6 and V8 models.

From the first quarter of 2006 the top-of-the-range model will enter the lists with an improved twelve-cylinder biturbo engine. Its output has increased by 12 kW/17 hp to 380 kW/517 hp, while the maximum torque has improved further from 800 to 830 Newton metres. The engine already makes this high torque available from 1900 rpm and maintains this level to 3500 rpm.

The eight-cylinder engine in the S 500 is a new development which will celebrate its world premiere in autumn 2005, together with the new S-Class. This power unit develops 285 kW/388 hp from a displacement of 5.5 litres, an increase of more than 26 percent versus the previous V8. At 530 Newton metres the torque also comfortably exceeds the maximum for the preceding engine by around 15 percent. This high level of torque is available from 2800 rpm and remains constant throughout a wide engine speed range up to 4800 rpm. Ideal conditions for powerful acceleration and fast intermediate sprints:

• The new S 500 accelerates from zero to 100 km/h in 5.4 seconds, and is therefore one second faster than the previous eight-cylinder Saloon.
• In third gear, the V8 Saloon sprints from 60 to 120 km/h in just 5.6 seconds.

The fact that the combined NEDC fuel consumption of 11.7 to 11.9 litres per 100 kilometres has remained at the level of the preceding model despite a higher output and more torque clearly demonstrates the efficiency of the up-to-date concept and high-tech features of the new Mercedes eight-cylinder unit.

With a specific fuel consumption of 233 grams per Kilowatt hour (g/kWh) at the best point in its characteristic map, and 345 g/kWh at part-throttle (2000 rpm, 2 bar), the engine has easily the lowest fuel consumption in this displacement and output class.

Key data for the petrol engines in the new S-Class at a glance:

*Available from first quarter of 2006

Powerful eight-cylinder unit as the highlight of a new engine generation

With the eight-cylinder unit for the S 500, Mercedes-Benz is presenting the top power unit in its new generation of V-engines, which was successfully introduced in mid-2004. This engine is produced in tandem with the six-cylinder engine of the S 350, at the DaimlerChrysler location in Stuttgart-Bad Cannstatt. This means that both engines belong to a single family and therefore share the attributes that make them prime examples of modern engine technology:

• High output
• Powerful torque
• Exemplary comfort
• Favourable fuel consumption
• Low exhaust emissions

In order to achieve these five development goals and exceed the previous standards, the engineers in Stuttgart developed an extensive technological package. Its components interact perfectly, complement each other in their effects and thereby achieve remarkable progress in every aspect.

Lightweight construction for smooth running and dynamic agility

A crankcase of diecast aluminium with low-friction aluminium/silicon cylinder liners is the solid and durable basis of the new Mercedes eight-cylinder engine. It houses a five-bearing, forged steel crankshaft with induction-hardened main and big-end bearings. The connecting rods are also of forged steel, with specific areas milled away to make them around one fifth lighter than those of the previous V8 engine for the S-Class.

Saving weight was not the only important aspect during the design work on the new engine, however. The engineers were just as determined to achieve the best possible results where smooth running and flexibility are concerned. Lightweight construction principles were helpful in this respect, for the lower the moving masses in the crankcase, the lower the vibrations and the more responsive the engine is to movements of the accelerator pedal.

The new eight-cylinder unit does not require a balancer shaft to improve its smoothness, for unlike in a V6 engine, a cylinder angle of 90 degrees is ideal for the vibration characteristics of the eight-cylinder powerplant.

Shifting camshafts for a perfect gas cycle and higher torque

Mercedes engineers have already used an intelligent valve control system in the new V6 engine, achieving remarkable progress and a major contribution to the good performance characteristics and low fuel consumption of the unit. In addition to four-valve technology, continuously adjustable intake and exhaust camshafts ensure that the cylinders are optimally supplied with fresh mixture. The valves are opened at precisely the right moment in any driving situation, significantly improving the gas cycle in the combustion chambers and reducing energy losses.

The camshafts are controlled by electro-hydraulically operated vane-type adjusters, which are located at the forward ends of the camshafts and are controlled by four integral hydraulic valves. The intake camshafts are driven by a duplex chain, while the exhaust camshafts are directly driven by the intake camshafts via a braced pair of gears.

In the new eight-cylinder engine the engineers at Mercedes-Benz have optimised the effect of this four-fold, continuous camshaft adjustment by using what are known as shifting camshafts. These control the opening of the exhaust valves and improve the engine’s gas cycle even further. Depending on the ignition sequence, the exhaust cams are designed in such a way that the valves open at different times during the exhaust cycle. This reduces the pressure fluctuations in the exhaust tract which are inherent to a V8 engine, and which lead to an inconsistent residual gas content in the cylinders.

The valve lift interval on the exhaust sides of the new Mercedes eight-cylinder engine is as follows:

• Cylinders 3, 4, 5, 7: 180 degrees crankshaft with 2 mm valve lift
• Cylinders 1, 2, 6, 8: 190 degrees crankshaft with 2 mm valve lift

The newly developed shifting camshafts improve the torque and smoothness of the V8 engine by ensuring a more uniform residual gas content, a higher knock limit and better cylinder charging in the lower to medium engine speed range. At 2000 rpm, for example, the effective mean pressure is around six percent (10.3 : 11.0 bar) higher than in a comparable engine without shifting camshafts.