I wish they had stated their ending battery mileage. When they began the Ike they were approaching .5 miles per kwh but did better on the downhill return trip back to Boulder. So maybe .75 mile/kwh at the end of the trip? I used to think that 1 mile/kwh was realistic for an EV towing heavy but that's probably a bit optimistic.
People like to hate on the TFL tow tests, but especially for electric vehicles they are pretty illuminating. Towing that lifted 4x4 on a flatbed might not be exactly like a travel trailer, but it obviously was not very aerodynamic. The TFL guys were a little perplexed that they didn't gain more charging while going down the Ike. I think it didn't occur to them that aerodynamic drag is always there whether you're going up or down. It takes a lot of energy to move an 8 foot high old pickup truck through the air at 60 mph.
