Im headed toward Washington DC at the end of May for the Rollingthunder POW/MIA meet... Ill be pulling a trailer with my 2 Harleys in it ... This will be the first time pulling a trailer that big 24ft..... Should I keep the O/D turned off while pulling on the iinterstate or is it ok to run it using the O/D. . lets say above 50mph?... ... . Rick