September 19th, 2020 by Steve Hanley
Lots of people talk about the towing capacity of their vehicles but there is actually an official protocol established by the Society of Automotive Engineers for measuring towing capacity. It involves towing a trailer up a steep grade on Arizona route 68 starting at an elevation of 550 feet above sea level in Bullhead City to a spot near Golden Valley at elevation 3,500 feet just 11.4 miles away. Oh, and there are two more pieces of the puzzle. The ambient air temperature has to be at least 100º F at the start of the climb and the truck doing the towing can not drop below 40 mph at any point during the journey uphill.
It is known in automotive circles as the Davis Dam Grade and in late August, Rivian brought one of its R1T electric pickup trucks and a dual axle trailer weighing 11,000 pounds to Bullard City to see if it could pass the test. Rivian has designed the R1T to tow that much weight. Did it have the right stuff?
According to a Rivian blog post, its validation team “made multiple runs on the Davis Dam Grade over two days while towing a 30-foot trailer loaded to this weight. And we did it under a blistering desert sun with temperatures topping out at around 118 degrees Fahrenheit.” The R1T passed the test without breaking a sweat, so to speak. “Beyond validation of our towing performance the team collected and assessed performance data to further refine the R1T systems and software for cabin comfort, torque control, efficiency and range.”
The official certification testing protocol behind them, the team next tackled Mount Charleston where the R1T was again asked to complete a long uphill climb — steeper and longer than the Davis Dam pull. Once again, the truck handled the task with ease.
But that wasn’t the end of the road trip. Next the team took the truck and trailer to Death Valley during a time when some of the highest temperatures ever recorded in the US were occurring on a daily basis. “Absolutely worst-case thermal. Worst-case grade. So you’re just looking to make it up the hill, essentially,” says Mike, a Rivian development engineer.
Despite the near-record heat, the R1T easily handled a winding climb from Stovepipe Wells, at an elevation just above sea level, to Towne Pass at 4,956 feet above sea level with grades as steep as 9.6% along the way. “When we reached Towne Pass successfully, that felt solid. It was such a corner case, outside the usual places people might go while towing. There are signs at the base of the route warning drivers not to overheat and to turn off A/C. If I’m able to make it there, I have good confidence in the system,” says Sushant, lead validation engineer for the company.
Finally the team visited Dumont Dunes to see if the R1T could tow the trailer through sand. “Dumont Dunes is kind of a quirky add-on for the trip. Can we take off comfortably in sand? Can we tow a trailer in sand? Yes and yes,” says Mike, the development engineer.
The entire journey is the subject of the video posted below. When it was over, Charlie, a power electronics systems engineer, gave a synopsis of the journey. “The R1T met all our targets. We hit our targets and did it without much of an issue. We tested for boundary cases and were able to go further. I really like working in teams like this — a collection of people with the same intrinsic motivation to bring a product to life. All the things that I came to Rivian for are here.”
Electric motors are all about torque and the Rivian R1T seems to have enough of it to run with anybody’s rig, even Ford, which posted a video of a prototype electric F-150 towing ten freight cars loaded with F-150’s last year. If you are a truck person and can’t wait to get your hands on an electric pickup truck that has some serious grunt, the next few years should bring lots of smiles your way.
Elon Musk says his Cybertruck will have enough torque to rip stumps out of the ground. General Motors is working hard on an electric pickup that will carry the storied Hummer brand forward into the electric vehicle future. We don’t know yet how much range any one of these vehicles will have while towing a trailer but we do know they all will have ferocious pulling power compared to their gas and diesel powered competition. For truck people, that may the most important metric of all.
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