New generation of engines with innovative technology

Sindelfingen, 28th October 2016

"Innovative? How can you call innovative petrol and diesel engines?" The daily newspaper colleague seated at the Mercedes TecDay beside me is appalled. He is clearly biased by the recently featured study Mercedes EQ on electric drive that glow are more or less old fashioned for him. But of course there are always innovations for Otto and diesel. You are also necessary, because we will drive all electric cars, probably decades before, whether it is good or not. As Mercedes introduces five new engines, produced from 2017 in the S-class.

New diesel with four and six cylinders

All new units are of course more economical and yet stronger than its predecessor. The innovations to established are very diverse. Introduced the new generation of engines was actually already in the spring of 2016, with the new two-litre diesel E-class. It consumes 13 percent less than the previous unit. Here among other things a lighter engine, an improved common-rail injection with up to 2,050 bar, as well as reduced friction by a wafer-thin iron coating of aluminium cylinder ("Nanoslide") result in savings.

Hot flue gas by Camtronic

Completely new is the corresponding six-cylinder diesel, which should afford 313 horsepower and seven percent less fuel swallows strong predecessor as the only 258 HP. The engine gets to the same technique and the same (close to engine) exhaust gas cleaning like the four-cylinder. But the SCR catalyst employed against nitrogen oxides is faster on working temperature, a so-called Camtronic is included here in addition. This valve ensures that the outlet valve remains open in the intake tract, so that in addition to (cold) air is sucked in (hot) exhaust. So the are limits also for the future prescribed RDE exhaust gas measurements. As the name suggests real driving emissions, be these measurements in normal road traffic, not on the chassis dynamometer. And they are carried down to refrigerator temperatures not T-Shirt temperatures, but a wide variety of conditions.

Technology-King: R6-Otto and 48-volt electrical system

The six-cylinder is undisputed king of technology at the new petrol engines. The engine strong according to Mercedes 'about 408 HP"to enable performance like an eight-cylinder, but consume about 15 percent of less than the V6 predecessors, who works in the today S 400 333 HP. Is responsible for the low consumption electric motor, which sits directly on the crankshaft between engine and gearbox 15 kilowatts (about 20 PS) under another one. This integrated starter generator (ISG) takes over not only the functions of starter and alternator and helps in the recovery of braking energy. He also has functions such as in a mild hybrid, which means that it helps when accelerating.

Electric compressor against the Turbo lag

For recuperation and boosting not the lead-acid battery and a lithium-ion battery used for energy storage here. The latter provides not the familiar twelve but equal 48 volt, also allowing much higher energy savings. The 12-volt network is maintained and supplied the electronics further. The ISG has to do even more in addition to its hybrid tasks: he drives the air compressor and the oil pump on, which eliminates the usual belt drive. The electric machine also supplies an electric auxiliary compressor. The bridge (similar to the Audi SQ7) time to "jump on" the turbocharger and intended to overcome so the Turbo lag.

The light version of the 48-volt network

Phew, so much complex technique at once! The corresponding four-cylinder petrol engine offers slightly less high-tech. The two-liter engine delivers a power of 100 kilowatts per liter of displacement so a total of about 270 HP. with his Twinscroll Turbo, This is on the level of older six-cylinder (like the V6 of the expiring E 320 Coupé), but significantly lower fuel consumption. Also here a 48-volt electrical system is introduced, but in a light version. The electric machine does not sit on the crankshaft, but is driven by a belt, and she's only ten kilowatts instead of 15. The belt-driven Starter/generator (RSG) assumes the recuperation, boosting at low speeds and drives the electric water pump. As the six-cylinder, a particulate filter is fitted to the exhaust gas cleaning. Mercedes introduced already 2014 the Otto particle filter in the S 500, without to hang it on the large Bell. Now, the technology is introduced gradually in all petrol engines for image reasons, as it is called at Mercedes.

V8 Twin-Turbo petrol engine producing over 476 HP

The last newcomer of our presentation round is a beefy V8 Twin-Turbo petrol engine. The 4.0 liter eight-cylinder supplies "over 476 HP" and torque of about 700 Newton meters. Despite the increased performance of the 4.8-liter V8 in the current S 500 provides "only" 455 HP fuel consumption by 10 percent should be lower. As the new six-cylinder diesel engine, it has a Camtronic here however used for the cylinder shut-off. It is active only on 3,250 tours and in comfort and eco modes. Then extend pins which move the sleeve-like pieces of the cams on the camshaft. Instead of eccentric cam are then active for the fair still cylinder zero cam (without lift) that lays down the intake and exhaust valves. At the same time, fuel and ignition for the closed combustion chambers are disabled. The shut-off and switching on to but not cause for the driver only by a note on the display, disturbing vibrations.

S-class with less than five litres consumption?

From career coating over the camshaft control up to the hybridization: The fuel economy measures in the new S-class engines are varied. Every engine needs something else, everything brings a few percent that adds up. The most economical conventionally powered S-class (the current S 350 d with 258 HP) currently has a standard consumption of 5.3 liters of diesel fuel. Whether the successor with the new six-cylinder auto igniter under 5.0 liter will come? I would bet on it. (sl)