Funny you bring this up. I picked up my kids from 6 flags in Gurnee IL. on the way home when I got on the tollway. I merged while seeing a F450 pulling a triple axle toy hauler in the left lane. He blew by me pretty good. once I was on the tollway and set the cruise at 75 to keep up with traffic (BTW traffic was heavy) the Fiver and truck were pulling away from me. I would guess his speed at around 83mph? I`ve even seen some motorhomes running at that speed. I personally set my cruise at 67 and sit back and relax. If I have to I`ve bumped it up to 73 on long boring stretches. but yes I`m seeing much more of 75+mph combos towing down the road!