It seems that I have all the intentions in the world of keeping my speed on the interstate at 62 to 65...but it creeps up...especially when you get south of Olympia, WA...it goes to 70 and soon I am cruising along...then it creeps up again! But that is when I have a destination and a sort of time table...on go no where in particular that day trips...it still creeps up, but it takes a little longer...then I notice it and drop back down and the cycle starts again. But I tell you the truck, tires, motor, boat trailer seem to like about 69, just settles into a groove! AWAY WE GO!!! Once in KS I did 90 for a few mins, long flat straight.