OM457

When Mercedes-Benz moved its heavy V-engines to the OM 500 series in 1996, the straight six was left out of the reorganization but handed the same technology. The OM 457 of 1998 replaced the OM 447’s inline pump with unit pumps set into the crankcase and driven off the camshaft, running to 1,800 bar under full electronic control, and raised compression to 18.5:1. That made one engine flexible enough to serve the European Axor, Brazilian production and — reworked as the MBE 4000 — Freightliner in North America. Euro IV, V and EEV versions added AdBlue and SCR.

In buses it went back on its side as the OM 457 hLA, under the Citaro, the Setra 300 and 400 series and the Travego. Its least likely home came late. The bonneted Zetros of 2010 was built for expedition, fire and military work far from any workshop, and the 2743 A and its heavier 3343, 3643 and 4043 relatives carry 428 PS with 2,100 N·m from 1,100 rpm. Production ran until 2013, by which time the clean-sheet OM 470 and OM 471 had taken over the heavy-duty range.