I run a Freightliner M2-112 with a Mercedes MBE 4000, 410 hp, producing 1450 ft-lb of torque. It’s mated to an Allison TRV-4000, 6 speed automatic transmission.
So far this set-up has provided enough power to pull my rig up hills in the south east US with no problem. Equally impressive is the downhill control with the 2 stage engine/exhaust brake. I get around 10.5 mpg pulling the loaded toyhauler. It’s very comfortable, easy to drive and has exceeded my expectations.
Having the 4 doors is great for passenger ingress and egress. The rear door windows and rear cab window provide greater visibility to surroundings, same as an LDT.