[emoji50] when it's windy and you have a tall trailer you need to drop your speed much more than that, think 55 or so. That trailer would have no problem flipping your truck. If you were doing 65-70 in windy conditions yes 10 mpg is what you should expect. The wind is whipping all over the place and not moving smoothly over the body, this requires much more power. Frontal area of the trailer is a big factor too. Just be happy you don't have the gas engines, you would have been down to 7-8 mpg. Sent from my SM-N975U using Tapatalk