On the way home from camping trip this weekend I snapped a pic of where my settings were during a long pull on I-81. If anyone is familiar with the southwest va section of I-81 at mm 114 there is a several mile long grade called Christiansburg mountain if you arw southbound. I was towing about 8500#'s up this grade and I started the climb at about 72. Topped the hill at about 68 and was a very happy man!