never pulled doubles..but have pulled a 36' 5th wheel alot. Dont forget to look back on the corners, swing wide, i dont know how many times i thought i was out far enough and looked back just in time to see me just about taking the end of the trailer off or wipeing out the fuel pump at the station. If you are going to pull a double i would recommend a sway bar on the trailing rig. i can pull my 36'er with my duramax as fast as i want, but past 80mph it starts to disagree with the meaning of "keepin it safe"