Mercedes-Benz Actros 2551 Used Trucks - Current Offers for Sale

Model Architecture and Engine Evolution

The Mercedes-Benz Actros 2551 is a 6x2 tractor unit optimized for heavy-duty logistics, specified for 25-tonne GVW chassis with a rated engine output of 510 hp (375 kW). Early MP3 variants (2010–2013) feature the 15.9L OM 502 LA V8, delivering 2,400 Nm torque via a PLD injection system, notable for its low-vibration and durability. The subsequent MP4 and Actros 5 generations transition to the OM 471 inline-six platform (12.8L), introducing X-Pulse amplified common rail injection. Torque increases to 2,500 Nm (Gen 1), with Gen 3 OM 471 (from 2022) raising compression to 20.3:1, max injection pressure to 2,700 bar, and introducing Top Torque mode to deliver 2,700 Nm in higher gears.

Chassis and Configurations

The Actros 2551 primarily utilizes a 6x2/4 tag axle configuration, offering optimal traction when the tag is lifted. Air suspension systems include intelligent axle load management with dynamic pressure assignment (Traction Help). Model variants comprise LS (air-suspended tractor), L (air-suspended rigid), and LL (full air-suspension) for specialized needs. Typical axle loads allow UK and Scandinavian markets to operate at the legal 44-tonne GCW.

Transmission and Braking Systems

Standard fitment is the Mercedes PowerShift 3 G 281-12 automated gearbox (12-speed, 2,810 Nm input rating) with direct-drive 12th gear. Transmission software includes selectable modes (Economy, Standard, Power) for tailored shifting and performance management. Secondary Water Retarder (SWR) is commonly specified, delivering up to 3,500 Nm braking torque while reducing weight and maintenance over oil-based retarders.

Cabin Technology and Aerodynamics

Cab configurations range from StreamSpace and BigSpace to GigaSpace (2.5m wide, up to 2.13m headroom). Actros 5 introduces MirrorCam and the Multimedia Cockpit with dual digital displays, with further aerodynamic enhancements via the ProCabin (from 2024): an 80mm extended nose and underbody paneling cut fuel use by 3%. Premium Actros L models add advanced insulation and a reduced seating H-point, while Actros F targets function-first fleets with conventional mirrors and classic analogue controls.