I've been through it a few times in various towing configurations. Once in an 07 5.4L Expedition towing a very small 8'x10' covered trailer with not much weight. No issues. The last four trips through have been in my 05 Superduty 6.0 diesel and had absolutely no problems with our 8K TT. This is our first year going South with my 2015 Superduty 6.2L gasser. I'm not really looking forward to it and am strongly considering staying on I75 to avoid this hill.