So I used my X for its first towing trip last night. This is a 110 mile trip that has a significant 4,500 elevation gain, mostly near the end up a small mountain followed by a 10 mile downhill stretch to the destination on the other side. In my P85 Model S, I would do this trip using about 130 rated miles going at a nice clip. Towing about 1,000 pounds on an open air 8'x5' utility trailer hauling a golf cart, it used 200 rated miles. I had range mode on, and drove the speed limit (65 on the freeway portion, 55 on the straight highway, relatively slowly on the mountain grade, just because I was being cautious with the trailer). On the freeway, it was using around 650 watts per mile, while the mountain grade it was using 850 watts per mile. Temperature was around 40 degrees. The car handled great, I barely felt I was pulling something, very stable. The trip computer didn't stand a chance. It estimated 33% range remaining at the end (starting with almost a full charge) and I got there with 19% remaining. The range estimate just slowly and steadily declined as the trip wore on. And while the car disengages auto steer while towing, it still allows you to use TACC which is nice. The one question I had is whether the car cooling system could handle the increased load, and I got no complaints from the car. I'll be doing the reverse trip in much hotter weather in 8 weeks, so we'll see what happens then. All in all, I'm very happy with the car's towing capabilities.