On Wed our 2500 towed 200m+ south on I-75 to Pigeon Forge, throught the hills of Eastern Ky, over Jellico Mtn and on to PF without a problem. More loaded than any of my earlier trips this year as I have gear for five, including a full bike rack on the back. Pulled Jellico, about a 3m+ grade, at a constant speed of 55mph at 3500rpm or less. The engine heat or tranny cooler did not budge. I love my truck!
2013 Sabre 36QBOK
2008 Ford F350 King Ranch CC DRW 6.4l, 4.10 diff
Airlift system/on board compressor