When working with the Imperial vehicles in Vehicle Turning Simulation, the minimum turning radius given is not the correct value. The value itself is different for the same vehicle in the Metric version. For example the AASHTO WB-50 vehicle in the metric database shows a minimum turning radius of 12.53 metres which converts to 41.109 feet. In the imperial database the minimum turning radius is given as 125.28 feet, out a factor of 3.0475.
I think there is something wrong with the conversion factors used in the software.