Out of Spec's R1T towing test impressions & results

[MountainBikeDude]

Summary by @vandy1981 :

No trailer @ 70mph: 2.2 miles/kWh
12 foot, single axle utility trailer (1100 pounds*) with 1500 pounds of payload @ 70mph: ~1.09 miles/kWh
12 foot, single axle utility trailer (1100 pounds*) with an 8x6 flat vertical panel @70 mph: ~.77 miles/kWh

They say that the total weight with 1500 pounds of payload is 3200, but the trailer I think they're using weighs around 1200 pounds.

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[MountainBikeDude]

@vandy1981

Thanks for adding the details @vandy1981 really appreciate that.

@OutofSpecKyle Thanks for making this video and for that matter, the series of videos and bringing us along for the ride.

 

[Forager]

Minor qualms with the test:

You’d be surprised at the drag coefficient of open grating like that trailer gate. It’s surprisingly high because that diamond pattern creates a lot of turbulence. I’d expect that on another flatbed trailer without a gate the efficiency would be improved, hard to say how much.

Placing the air dam at the rear of the trailer puts the air dam in the slipstream of the truck, where air is resuming laminar flow. This will make the aero worse than if the air dam were at the front of the trailer like car haulers with protective fairings or box trailers. So I’d say this is the very lower bound for trailer efficiency.

Overall, I’m pretty impressed with the effort these guys are putting in.

 

[Harvest]

I agree with Forager1 that the placement of the air dam that far behind the truck is different than a standard RV or cargo trailer. Regardless, this test points out the importance of air resistance on trailers in general, and especially for EV towing. I wonder if there are any RV trailer designers who actually use wind tunnels to fine tune their design. Most RV's don't look very aerodynamic, including Airstream.

Great job by Kyle and team - really putting in the effort pulling some long hours. Really appreciate all the detail being provided. I've already learned a lot from him that I hadn't heard in the other 30 plus videos I've watched of the R1T.

 

[kizamybute']

Wow, only a 1,700 lb trailer. Given, they added drag with that tailgate setup, but still, the trailer is ONLY 1,700 lbs. What if you added a 3,500 car to that trailer? At just 1,700 lbs, only 0.77 mile per kWh is pretty rough. Not sure how many would have a need to two an empty trailer. Figure adding weight is going to further impact those numbers. Would like to have seen them leave the 1,500 pound payload in the trailer. '

Basically, well under 100 miles of towing range in cold weather.

Even without the tailgate wood, towing 3,200 lbs netted just 1 mile per kWh.

Point being, as has already been pretty clear, we're still a long ways off from EV's being practical tow vehicles.

For me, probably could squeak by making my run to the local lake about 45 miles away. With warmer temperature, should be able to make the round trip with a 6,000 lb trailer. But, sure as heck wouldn't consider using it to go on one of our 400 mile trips up north. Having to stop and charge for and hour and a half every 100 miles, plus actual drive time, would turn a 6 1/2 hour trip into a 12 1/2 hour trip. 25 hours for round trip. Yeah, no thanks on that one!! LOL

Same would true of trying to tow an RV trailer the same distance.

EV's are great for local use, absolutely worth it. But, definitely not ready for long distance camping or boat trips yet.

 

[Ventura]

It sure does seem like aerodynamics matter more than weight at high speed. I wonder what the test would look like around town (45mph or less). The answer will likely be a combination of more battery (trailer or tow vehicle) and better trailers. Image below just a more fun version of standard drag vs speed graph.

 

[Inkedsphynx]

Once you get the weight up to speed, inertia helps a lot, so yes, I'd agree that aerodynamics are vastly more important than the amount of weight in the back, and you can't take that 1500lbs as any 1500lb load, since the trailer they were using, even without the wood setup, would have generated a fair bit of drag.

 

[Polecat]

I agree with Forager1 that the placement of the air dam that far behind the truck is different than a standard RV or cargo trailer. Regardless, this test points out the importance of air resistance on trailers in general, and especially for EV towing. I wonder if there are any RV trailer designers who actually use wind tunnels to fine tune their design. Most RV's don't look very aerodynamic, including Airstream.

Great job by Kyle and team - really putting in the effort pulling some long hours. Really appreciate all the detail being provided. I've already learned a lot from him that I hadn't heard in the other 30 plus videos I've watched of the R1T.

I found a company that makes a “teardrop” that is supposedly designed for aerodynamics with EVs towing in mind.
https://www.polydrops.com/

Bit of an unexpected shape but if it works?

 

[Speedrye]

Non-towing items I noted:
Headlight/foglight output looked good, though the cutoff looked a bit low.
Interior screen dimming looked to have a good range, even if some settings need more work from Rivian.
Standard cruise! I'm hoping this is available outside of towing mode and that I'm not forced to use adaptive cruise.

 

[Forager]

Something which didn’t immediately come to mind while watching this video is that air density at 5000ft is 85% of that at sea level. So the range tests in Colorado are actually going to be favorable compared to the same tests along the coast.

 

[jdhiker23]

Fantastic test @OutofSpecKyle - thank you for staying up late to get the data under consistent conditions!

I know it was already too late at night, but it would be really great to do the exact same test with another EV towing the same trailer to see how consistent the increased energy consumption from towing is from one vehicle to another (ie - does the kWh/mile increase by the same amount when you add the same trailer on the same route to different vehicles). I'm guessing that the energy usage to pull the trailer is pretty constant no matter what vehicle is pulling it (at least for that trailer given the wind load is so far back beyond the towing vehicle).

If vehicle and trailer efficiency are independent, it becomes easy to log trailer energy consumption data on one vehicle and then use that to calculate accurate towing range for that trailer under similar conditions on pretty much any EV, then load that data into a route planner like ABRP.

 

[sac602]

This makes me wonder how much a rtt (on roof) would impact range. Mostly relevant to R1S.

 

[Forager]

This makes me wonder how much a rtt (on roof) would impact range. Mostly relevant to R1S.

I believe they have that test planned: RTT on/off bed and maybe roof?

 

[camaroz1985]

Waiting to see the test with the enclosed car hauler. Based on what you get with that I may be switching from Max to large battery.

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