Mercedes-Benz E-Class: Three new high-tech engines join the line-up

Stuttgart, Dec 12, 2002 -- Launched successfully in March of this year, the E-Class is now set to benefit from an even wider range of engines: customers can specify the innovative Mercedes-Benz Saloon with a newly developed supercharged engine, an economical four-cylinder CDI unit or an advanced six-cylinder diesel. These new arrivals mean that the E-Class is now available with nine state-of-the-art engines with outputs ranging from 90 kW/122 hp to 350 kW/476 hp.

The E 200 KOMPRESSOR four-cylinder unit belongs to the latest generation of Mercedes-Benz engines which is distinguished by the unique TWINPULSE system. It uses a combination of different technologies - such as supercharging, charge-air cooling, four-valves per cylinder, fully variable camshaft adjustment and a Lanchester balancer - to deliver a maximum of driving enjoyment and smoothness while keeping fuel consumption to a minimum.

On the basis of the NEDC measurement method, the new 120 kW/163 hp four-cylinder unit consumes just 8.4 litres of premium unleaded petrol per 100 kilometres, a saving of some 0.7 litres compared with its predecessor which had the same power output. The top speed of the new E 200 KOMPRESSOR increases to 230 km/h (predecessor: 222 km/h).

The Mercedes engineers achieved these exemplary fuel consumption figures principally by shifting the operating points into engine speed ranges offering optimum thermodynamic efficiency. The reduction of the displacement to 1.8 litres also had a positive effect on consumption figures thanks to lower friction losses and improved thermodynamics. The engine achieves its maximum torque of 240 Newton metres between 3000 and 4000 rpm.

Thanks to the TWINPULSE system, the unique combination of supercharger and Lanchester balancer resolves one of the paradoxes encountered in the development of four-cylinder engines: the balancer shafts compensate for the vibrations inherent to this type of engine and thus ensure a level of smoothness which is exemplary in this engine size class. In other words, by using supercharging and the very latest engine technology, the new four-cylinder powerplant in the E-Class combines the pulling power and low noise levels of a six-cylinder unit with the economy of a four-cylinder engine.

Aluminium cylinder head with fully variable camshaft adjustment

Manufactured in high-strength aluminium alloy, the cylinder head is equipped with 16 valves and two overhead camshafts. Unlike previous four-cylinder engines from Mercedes, there is fully variable adjustment of both camshafts. A newly developed vane-type adjuster with an integrated control valve optimises the valve timing by allowing it to be adjusted continuously. This has a positive effect on torque characteristics at full throttle, on fuel consumption and on exhaust emissions. The valves are controlled by roller cam followers and feature maintenance-free hydraulic valve play compensation.

E 200 CDI: a range of over 1000 km on a single tank

From January 2003, Mercedes-Benz will be offering a particularly economical entry-level E-Class model in the form of the new E 200 CDI. This 90 kW/122 hp four-cylinder diesel unit, which is distinguished by its second-generation common-rail direct injection technology, makes do with just 6.3 litres of fuel per 100 kilometres (NEDC combined). With a tank capacity of 65 litres, this means that the Saloon has a range of more than 1000 kilometres.

Thanks to its increased maximum firing pressure (up from 145 to 155 bar) and optimised in-cylinder gas cycle, the bottom-end pulling power and flexibility of the four-cylinder unit are significantly better than those of its predecessor (85 kW/116 hp). This improvement is also due in part to another new feature: the VNT turbocharger with electrically adjustable guide vanes. This technology enables even more dynamic and precise supercharging than that obtained with the previous vacuum-controlled system. The guide vanes are adjusted in line with a map stored in the electronic engine management unit. The result: a faster build-up of charge pressure at low revs and, consequently, substantially more pulling power.

This advanced CDI powerplant delivers its maximum torque of 270 Newton metres from just 1400 rpm, an improvement of more than seven percent compared with the figure for the previous E 200 CDI (W 210 model series). The new E 200 CDI accelerates from 0 to 100 km/h in 12.1 seconds and has a top speed of 203 km/h.

Newly developed injector nozzles and injection pressure of 1600 bar

Another important feature of the second-generation common-rail engines is the newly developed seven-hole injector nozzle which replaces the previously used six-hole nozzle. The new injector permits a 20 percent reduction in the size of the nozzle hole diameter. Not to mention a cut of some 14 percent in the fuel flow rate. As a result, the fuel is even more finely dispersed in the combustion chambers and carburetion is improved. However, the greater flow restriction - due to the smaller nozzle holes - prolongs the injection period, which has a particularly adverse effect when power delivery is high. This is why the Mercedes engineers have increased the injection pressure from 1350 bar to 1600 bar, thus shortening the injection period. As in all CDI engines, this high pressure is immediately available at all times.

Double pilot injection ensures lower operating noise

The leading-edge common-rail technology also gave the Stuttgart specialists the opportunity to make further progress in the field of low-noise operation. Double pilot injection is what makes it possible: a few milliseconds before actual fuel injection takes place, small amounts of diesel are injected into the cylinders twice in rapid succession. This fuel then ignites, thus preheating the combustion chambers. This provides a better basis for the subsequent main-injection phase, since fuel ignition is faster in the preheated cylinders. Therefore, pressure and temperature no longer rise as abruptly as is the case in engines without pilot injection. This has a favourable effect on combustion noise.

E 320 CDI: agile six-cylinder diesel with 500 Newton metres of torque

A 3.2-litre six-cylinder powerplant is the other newcomer to the range of diesel engines for the E-Class. It has the same technical features as the common-rail unit fitted in the E 200 CDI: seven-hole injector nozzles, injection pressure of 1600 bar, double pilot injection and a VNT turbocharger with electrically adjustable guide vanes. These features result in enhanced performance, increased torque, lower fuel consumption and reduced operating noise.

The six-cylinder engine has an output of 150 kW/204 hp (predecessor: 145 kW/197 hp) and maximum torque of 500 Newton metres from 1800 rpm (predecessor: 470 Newton metres). The NEDC combined fuel consumption of the E 320 CDI is just 6.9 litres per 100 kilometres - a saving of 0.9 litres compared with the predecessor model. The increased firing pressure (up from 145 to 155 bar) in the combustion chambers and the optimised in-cylinder gas cycle improve the saloon's bottom-end pulling power significantly: 250 Newton metres of torque are available from just 1000 rpm, rising to 420 Newton metres from 1400 rpm. The E 320 CDI accelerates from 0 to 100 km/h in 7.7 seconds, an improvement of some 0.6 seconds on its predecessor (W 210 model series). It has a top speed of 243 km/h (predecessor: 230 km/h).

Although New-Cars.com checks with auto manufacturers and their representatives to confirm the accuracy of the data, it makes no guarantee or warranty, either expressed or implied with respect to the data presented here. All specifications, prices and equipment are subject to change without notice.

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