Mercedes-Benz Vehicles is introducing the third technology of its OM 471 heavy-duty diesel engine this yr; the engine will ship elevated gas effectivity and compliance with the strictest emissions requirements akin to Euro VIe.
The third technology of the OM 471 put in within the Mercedes-Benz Actros and the Mercedes-Benz Arocs options plenty of technical improvements aimed toward decreasing the Complete Price of Possession (TCO) when it comes to fuel-saving driving, decrease working prices and better yields, with out sacrificing efficiency, driving dynamics or driving consolation, stated Christoph Mertens, Mission Supervisor for the brand new engine at Daimler Truck.
Additional optimized combustion, application-oriented turbochargers and decreased friction. The enhancements in effectivity for the third technology of the OM 471 are the results of plenty of engine improvements. For instance, the geometry of the piston recess, the injection nozzle design and the parameters of the cylinder head related for fuel alternate have been topic to an intensive optimization course of. On this manner, the compression ratio of the six-cylinder in-line engine has been elevated from 18.3:1 to twenty.3:1; this results in extra environment friendly combustion with a peak ignition stress of 250 bar.
Heat aspect (high) and chilly aspect (backside) of OM 471 engine
Probably the most necessary levers in rising gas effectivity in fashionable diesel combustion engines is turbocharging optimization. With the third technology of the OM 471, Mercedes-Benz Vehicles is introducing two new turbochargers developed and manufactured in-house that are exactly tailored to the broad vary of buyer necessities. Within the consumption-optimized variant, the main focus is on the bottom potential gas consumption; it’s predestined to be used in long-distance haulage with an engine rated at as much as 350 kW (476 hp).
The second turbocharger variant is designed for top efficiency and a excessive engine braking pressure and is right to be used within the heavy-duty- and development sector with an engine score of as much as 390 kW (530 hp). For the lower- and medium-performance ranges of the OM 471, the utmost gas saving in contrast with the earlier technology is as much as 4%, and for the higher efficiency ranges as much as 3.5%. The high-power variant can be used within the decrease efficiency ranges for the development purposes of the Arocs.
Decreased friction losses and stress management with low-viscosity oil. Along with combustion and turbocharging, friction discount is the third necessary lever for bettering gas effectivity.
For this goal, the third-generation OM 471 has a newly developed engine oil stress management valve. It’s put in behind the engine oil pump and in entrance of the oil thermostat. {An electrical} actuator permits traits map-controlled use of the pressure-reducing valve. Out there reductions in engine oil stress are decided in a fancy matrix that takes under consideration all engine parts and their particular necessities, akin to lubrication or cooling.
A newly-developed engine oil with low viscosity enhances oil stress management and improves gas effectivity with out decreasing oil change intervals or rising the wear and tear on affected engine parts.
Newly-developed exhaust fuel aftertreatment system. The exhaust fuel aftertreatment system, which has been utterly revamped and tailored to the brand new combustion and management system of the OM 471, additionally helps enhance gas effectivity.
The system limits the counterpressure and likewise will increase the uniformity index of the AdBlue, which results in improved NOx conversion and decrease gas consumption. The NOx sensors along with the closed and adaptive NOx closed-loop management circuit and a predictive SCR temperature mannequin have enabled emission stability to be improved even additional.
It’s even compliant with the strictest emission requirements, akin to Euro VIe, which name for efficient limitation of exhaust fuel emissions over the whole regular service lifetime of a car beneath regular utilization situations.
PowerShift Superior and High Torque. Alongside profitability, robustness and reliability, Mercedes-Benz Vehicles has as soon as once more turned its consideration to a different necessary issue for purchasers within the third technology of the OM 471: driving dynamics. Engineers centered on the drivetrain for this goal.
For instance, the brand new PowerShift Superior automated transmission management permits quicker and smoother shifting off and acceleration in lots of conditions thanks to specific gear choice. Quicker gear adjustments scale back the torque interruption time by as much as 40% within the higher vary.
Accelerator pedal parameterization has additionally been additional optimized: Elevated sensitivity within the decrease pedal journey permits considerably extra delicate maneuvering, whereas the direct response time within the higher pedal journey leads to elevated dynamics beneath excessive load necessities. It additionally makes it simpler to drive round, and speed up out of roundabouts.
One other spotlight is the prolonged High Torque vary. Out there for engine output ranges 330 kW (450 hp) and 350 kW (476 hp) along side the G281 transmission, a strong 200 N·m torque is offered to the crankshaft in gears 7 to 12 within the “A Customary” program.
