The 12.8-litre, 6-cylinder engine is claimed to reduce fuel consumption by up to 4% while complying with the latest Euro-6e emissions standard.
The new engine has been thoroughly revised throughout. From the inside, piston bowl shape, injection nozzle and gas flow have all been optimised for efficiency.
The compression ratio has been given a significant rise from 18.3:1 to 20.3:1, giving a peak combustion pressure of 250bar. The pressure of the newly developed low-viscosity engine oil is now controlled electronically, variable according to immediate needs.
The requirements of different types of operation are now met by two different in-house turbocharger designs. The first is focused on fuel economy on long-haul operations, and is available on engines nominally rated up to 470hp (350kW). A different type giving greater performance and increased engine braking is fitted to higher-power versions of the Actros, up to 530hp (390kW) ratings, as well as to the lower-powered engines when used in construction versions of the Arocs. A redesigned exhaust aftertreatment system reduces back-pressure and allows more consistent AdBlue dosing rates.
To match the new engines, an enhanced Powershift Advanced transmission control system is said to offer more precise and faster gear changes, with a reduction in torque interruption times of up to 40%. The Top Torque feature, available on 450hp and 480hp ratings with the G281 transmission, now allows an extra 200Nm in gears 7-12 in normal use.
Mercedes-Benz Trucks boss Karin Rådström said: “With the third generation of the OM 471, we consistently focused on the needs of our customers. Our goal was to decrease the total cost of ownership and reduce fuel consumption. Our customers will benefit, as will the environment.” The new OM 471 is available to order now, with delivery from October 2022.