[Jeff Teuton]

Of course you know Benz owns Freightliner, so that is the standard motor, and the larger DD and Cummins and Cat (when they made them) are an extra cost option. The 450 if I remember makes 100 ft/lb less tqe than the other motors. I think the other motors (depending on year) make 1650 tqe. I think those have to be detuned for an Allison, but the clutchless computer trans will stand the 1650 and the Allison will handle 1550. The new combos are using the 600 Cummins with 1850 tqe which require a larger trans mainly the main shafts have to be much stronger. I don't know about the endurance of the MB 450, and I don't know how big the motor is. Most of the other brands are 14L or 15L or so I don't know. Cummins makes an 11L motor @ 450 I think and has been a good piece. Runs at higher RPM. Most are governed at about 18 to 1900 rpm. Peak around 1300 or so. I would rely on the dealer or someone from a large fleet for info. I don't know if this helps. We make sure all the motors in our fleet are full of DCA which prevents the fault you are speaking of. If you let those trucks sit around without DCA in the water system, it will have plenty of time to make holes in the cylinder walls. We have about 1500 lease trucks, and do service a couple hundred more. We are a KW dealer so we don't have too much experience with those other than fleets we buy out and has some of them in the fleet. I like the meritor trans better. It's not as efficient as the Eaton brand, but it backs up much better. Also had less trouble with them as opposed to the Eaton.