Tug of War on Pavement: R1T vs F350 Tremor

[Zoidz]

Despite the differences in tires and surface area contacting the ground, the T rarely broke traction often having wheels rotating backwards, so I think that's about as fair a test as it could be. Despite the loss, I love watching videos that test the limits, this and the roller test video you guys did were super informative.
Cheers.

You are assuming that the Rivian is programmed to continue applying full forward power regardless of what is detected, like an ICE would do. I think the programming is preventing forward direction spinning because it is detecting a stall condition, regardless of traction control.

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[Thedude]

The computer control definitely limits the Rivian in some ways. I noticed this trying to help free a friend’s class A RV from the mud. As soon as the tow strap went tight and the R1T encountered significant resistance to forward movement it cut out power in all drive modes. The ICE truck another friend used would allow the tires to spin and scrabble for traction rather than just cutting out.

 

[Ecupip]

This "test" is very lame. With low range and enough weight, most ice trucks will win this test. The gearing advantage is too much.

I wish they had tested the Ford in 4X4 HI to see what that result would have been.

 

[Blueassassin]

Great video cool product. Agreed as we see it on all the tests where people are trying to rock crawl the Rivian it needs gearing a low drive for crawling and a pulling test like this. Trouble is very little of us use it for that and its probably not worth the extra complexity, moving components, and weight.

 

[Dirtcom_AJ]

To illustrate the concept, imagine the F350 with bicycle tires. Hopefully everyone agrees that the Rivian would have won that competition hands down. So while this was a fun demonstration, it doesn't really prove much.

The Rivian has 10,325 lb-ft of "grounded torque" (quoted Richard Farquhar VP Propulsion) through a 12.6:1 gear ratio (EPA Test info). This equates to about a 10% drivetrain loss (908 lb-ft) which is actually really good and makes sense considering there is no parasitic loss due to transmissions and transfer cases.

The Ford numbers can be a little more confusing. Specs show 465 hp and 1050 lb-ft torque (at the crank?). If you did a theoretical calculation of the rated 1050 lb ft torque and multiplied by trans x transfer case x rear diff you get a huge number even if you consider a 30% drivetrain loss. So in 1st gear at 4.6:1 x 4 lo at 2.6:1 × 3.55:1 rear diff x 1,050 lb-ft we are already at 31,000 lb-ft of torque at the wheels. Even with similar grounded torque number the Ford can achieve slower wheel speeds with the higher torque and keep traction. Anyway it's a confusing rabbit hole that only leads to more questions...

Yes the test was definitely fun but ith isn't just about winning or losing. We can learn much more. One important aspect I learned is that even with "traction control off" the Rivian is still limiting power. Rather than the rear tires losing traction and peeling out they simply spun backwards in sport mode as others have pointed out. Maybe drift mode would have been different but then we don't have full 4x4. It's obvious that the Rivian traction control is very sophisticated and probably for our own good... but sometimes I don't want to be good.

Additional Weight in test Rivian = 389 lbs
Front Runner Roof top tent = 93 lbs
Front Runner SLIMLINE II LOAD BED RACK KIT = 86 lbs.
Front Runner SLIMLINE II ROOF RACK KIT = 64 lbs
Apollo Ghost Escooter in Gear Tunnel = 64 lbs
Camping gear Estimated = 70 lbs
Wheels 43 lbs vs stock 40 lbs = 12 lbs

We have a 2022 Tundra here at the shop that I could do a tug of war against but I'm not sure it's worth the hassle? hahahha.

 

[OrthoBlock]

It's likely that the Rivian torque limiting is implemented to prevent overheating of the motors/inverters and/or mechanical damage to the drive train. In the 3rd test, you can see that the front wheels are spinning forward for a bit while the rear are turning backwards, and then it appears that the front wheels "give up" and start turning backwards. From a programming viewpoint, if you are commanding all four wheels forward, but detect one or more are turning backwards, you know something is not working, and limiting torque is a smart preventative step.

...or could it simply be that the Rivian doesn't have enough torque to overcome the the static friction (while the truck is not moving initially, and the tires are in fixed contact with the ground), but once the truck starts sliding backwards then the tires are subject to the dynamic friction, which is lower, and the truck does have enough torque to overcome this lower hurdle and thus the wheels finally rotate when the resistance to spin is lower.

I don't know the answer, but the observed data appears consistent with this.

 

[EVnewb]

As stated earlier, thank you for testing the limits of the truck!

Did Rivian mess with the drive modes since last winter? I remember that R1T owner pulling that semi out from being stuck on the side of the highway. His tires were squealing and smoking a little from all the wheel spin as he pulled that semi out and back onto the road. Was that because of the running start to get the inertia in the wheels going?

 

[NY_Rob]

The Ford has a nice loose liquid coupled torque converter in the tranny that lets the ICE spin up to it's full rated power RPM without damaging any systems.. and it also starts off in low gear. You don't have any of that with a direct driven gear train powered by an electric motor. Easiest way to burn out any electric motor is to lock up the rotor and apply full power. The Rivian monitoring system noted the full power input to the electric motors and also noted the wheels weren't turning.. so it reduced power significantly to protect the system components (inverters, wiring, motors and even the battery). If the Rivian was on sand, gravel or dirt it probably would have been spinning the tires with TC set to off.

 

[srkz]

Proof that it’s got nothing to do with the Ford’s torque:

Have the Rivian pull while the Ford just sits there with its brakes fully locked and it still won’t move.

 

[Green Mean Machine]

First of all, I have put over 12,000 miles on my R1T in 5 months and I still love it today. For an all around vehicle nothing beats it.

As shown in our previous 4x4 roller test video, the quad motor could use a transfer case or even some sort of "simulated locker" to really perform excellent in low speed crawl scenarios. Understandably this wasn't designed to be a rock crawler. Handling and traction control is amazing at medium to high speeds in offroad scenarios which is a compromise I am willing to accept. (but still frustrating only because I know it can be better)

In the beginning of the video we go over our tug of war setup (because safety is important) while simultaneously promoting our product. If you want to skip straight to the 3 pulls we did they start around 3:45 mark. ENJOY!!!

EDIT: IMORTANT CONTEXT ADDED
1. With our knowledge from our previous 4x4 roller test I floor the accelerator pedal QUICKLY in pull 2 and 3. Even with "traction control off" I believe the Rivian computers are still limiting wheel speed! Too smart to let us have fun? hahahah.

2. The curb weight of the Ford F350 is 6,769 lbs and it is NOT heavier than the Rivian.

3. The Rivian has a documented axle ratio of 12.6:1. The "ground torque" is quoted to be 14,000 Nm which is 10,325 lb-ft. If you do the math thats about 10% drivetrain loss. (Which is really good)

You need to put the R1T in Tow mode since you're trying to tow the Ford. That will give you more traction. Also have the truck in offroad mode as well.

 

[Zybane]

lol at all the excuses. The amount of Torque that the Rivian can actually put down at low speed is actually pretty lame compared to an ICE vehicle with a torque converter and a low-range transfer case. One of the main reasons why the Rivian is mediocre at best at slow speed off-road. With a 7K lb+ weight, even small obstacles overwhelm the Rivians motor-current/torque output.

 

[Dirtcom_AJ]

The amount of Torque that the Rivian can actually put down at low speed is actually pretty lame compared to an ICE vehicle with a torque converter and a low-range transfer case. One of the main reasons why the Rivian is mediocre at best at slow speed off-road. With a 7K lb+ weight, even small obstacles overwhelm the Rivians motor-current/torque output.

Yes this is why we decided it wasn't worth it to do every single drive mode. I try to explain the numbers in a previous post, but perhaps not everyone understands this. When we get bigger tires on the Rivian it might help a little bit.

Low torque in low speed but the beauty of the Rivian is the instant torque and acceleration ones it gets going!

 

[Zybane]

Larger tires reduce wheel torque not increase it.

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