I have a 110, 200tdi with the disco box, on 235/80s.
I tow and move up to 1 ton of boat and trailer, up to 25 miles in Norfolk no problem.
I drive up to 200 miles in a single trip, not towing, half "A " road, half A1/A1M, I find the disco box much better, quieter, for comparatively high speed...