I have a 2008 2350 (E350 w/V-10) with which I transport a motorcycle on a Versahaul rack having a 600 LB capacity, and behind that I tow 4 wheels down a 2008 Suzuki SX4 2X/AWD/4X with 5 speed manual transmission using a Roadmaster Sterling all-terrain non-binding tow gear. This set-up tows extremely well. Since the "toad" vehicle is just under 3000 LB., in many states it doesn't require an auxiliary brake unit. Without auxilliary brake in the toad the "to-Haul" feature of the RV holds the composit rig to the speed set on the cruise control on as much as 6-7% downgrades, but steeper grades need minor assistance about every 2 miles from the rig's brakes. Fuel mileage goes down approximately 1 MPG while towing. See ya at the Plymouth gathering if you're going. Cheers.
