I drive a 2008 Dodge Ram 1500. It has 2wd, 4hi, and 4lo. I have heard from some old timers that if I drive in 4hi at highway speeds it will damage the vehicle. The manual does not say anything about not driving highway speeds in 4hi. I only drive in 4 hi when there is lots of snow on the road (I-25/I-70 between Colorado Springs and the mountains mostly). Does anyone have any good info on this? I understand how 4hi is no good on dry pavement (I've made that mistake a few times), but in a snowy situation on the interstate where I am not making any turns, only highway curves, is there anything wrong with it? I am talking speeds like 50-70 mph. Thanks for any info you have, my father and I have the same truck and this will solve some debates.