Welcome to iRV2. 100 pounds per horse power is something for you to consider. 200X100 = 20K pounds. If the weight of the coach and towed car is more than 20K, then patience will be needed. I speak from experience. My coach is 330 Cummins and I am moving 37K+ down the road. On flat or moderate inclines, the Cummins does fine (60 MPH). In the mountains (Smoky or Rocky) I'm usually in the truck lane admiring the view. It all depends on if momentum can be kept.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours