When deviating from a route the zūmo XT will try to get you back to the point where you deviated from the route, even when recalculating to the next route-point would be faster. It will do this until you are about a mile from the original route. Often the zūmo XT will insist on making U-Turns. Hence the abbreviation RUT, that stands for Repeated U-Turns.
Most people consider Repeated U-Turns a problem, and would prefer recalculating to the next route-point, if that's faster.
If you disable U-turns, the zūmo XT's behaviour will change slightly, but it will still not aim for the next route point.
Multiple tests carried out, reveal that when a trip is created on the zūmo XT itself, it will recalculate to the next Route point. If a trip is imported from an external planner, like BaseCamp or MyRoute app, it will demand U-Turns. You can check this by opening the Trip planner, trips will either be listed under "Saved Trips", or under "Imported Trips".
All trips in the trip planner are stored in Internal storage/.System/Trips as nnnnnnnn.trip files. In these files there is a flag called "mImported" that defines whether a file is listed under "Saved" or under "Imported". Modifying this flag by setting the value to "00", will result in the file being listed under "Saved". And not only is it listed under "Saved" it will also behave like a Saved trip. That is, it will not direct you to make U-Turns, but it will recalculate to the next route-point. Of course if a U-turn would be faster it will demand for a U-turn.
Thanks to all members of the Zumo Users Forum who contributed. Also you can find more info by following this link.This tool was inspired by a Java program created by FrankB.