Scorpion AS+ tire swap (from 20" Scorpion AT) - WOW big difference

[anthonysfl]

You can't compare those two, every vehicle is different. Even if I tricked my R1T out the same way as yours, we'll get different consumption on the same drive. For true improvement numbers, you need the exact same rig with nearly identical road conditions.

I can make a comparison between the two. Correct, it’s not truly an exact comparison, but it’s the closest anyones been able to comment on with the 20’s AS versus 21’s setup on any of these forums. Most of these forums people bash each other and complain they get better numbers or worse numbers than each other. Unless you’re driving the same exact route as someone else, all those comments have no merit. I drove the exact same route. That is the point. Until we find two people with the same model Rivians, one with 21’s and one with 20’s on AS tires, my experience has been the some of most evidence we have had thus far.
It’s safe to assume the R1T is more aerodynamic than the S. If that were not true, than the S would get 347 in conserve mode like the T does, but it does not. It gets 328. It’s also safe to say that running boards and mudflaps may increase drag and reduce aerodynamics.
So again, my R1T was in its most efficient form. 21’s with aero caps on, conserve mode low. For my S, with 20 AT brights in conserve mode low on AS tires, with mudflaps and running boards to get a marginally higher mi/kWh on the exact same route, albeit worse weather conditions, is pretty good data.

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[mkhuffman]

I can make a comparison between the two. Correct, it’s not truly an exact comparison, but it’s the closest anyones been able to comment on with the 20’s AS versus 21’s setup on any of these forums. Most of these forums people bash each other and complain they get better numbers or worse numbers than each other. Unless you’re driving the same exact route as someone else, all those comments have no merit. I drove the exact same route. That is the point. Until we find two people with the same model Rivians, one with 21’s and one with 20’s on AS tires, my experience has been the some of most evidence we have had thus far.
It’s safe to assume the R1T is more aerodynamic than the S. If that were not true, than the S would get 347 in conserve mode like the T does, but it does not. It gets 328. It’s also safe to say that running boards and mudflaps may increase drag and reduce aerodynamics.
So again, my R1T was in its most efficient form. 21’s with aero caps on, conserve mode low. For my S, with 20 AT brights in conserve mode low on AS tires, with mudflaps and running boards to get a marginally higher mi/kWh on the exact same route, albeit worse weather conditions, is pretty good data.

I am confused regarding your post. The last paragraph suggests the S is more aerodynamic because it has a less efficient wheel configuration and added features that will increase air resistance, yet you are getting better efficiency with it.

 

[Riviot]

the best I had with my R1T on 21’s for that same trip was 2.2 mi/kW

Ahh, my bad. I missed the 21s part. Coffee hasn't kicked in ?

 

[Riviot]

I am confused regarding your post. The last paragraph suggests the S is more aerodynamic because it has a less efficient wheel configuration and added features that will increase air resistance, yet you are getting better efficiency with it.

Who's on first

 

[anthonysfl]

I am confused regarding your post. The last paragraph suggests the S is more aerodynamic because it has a less efficient wheel configuration and added features that will increase air resistance, yet you are getting better efficiency with it.

Ok, so let’s start from the beginning. It’s safe to say the T is more aerodynamic than the S because the T gets 347 in conserve mode versus the S 328. That is with the 21” wheels with aero caps inserted from Rivian.
This thread is about efficiency of the 20 inch wheels on AS tires compared to the 20 inch wheels on AT. I took it a step further and posted a couple of YouTube videos from engineering explained who nicely points out that the most efficient setup is the smallest diameter wheel on the same size tire. Thus, my claim that any 20 inch forged wheel on 275/60/20 is more efficient that the 21 setup from Rivian. His video explains it all.
So, when I got my S. I swapped the 22’s and put on the Rivian 20 inch wheels with 275/60/20 Pirelli AS 3. I also put on mudflaps and running boards from EVSportline. Now, my experience with my driving trips to Disney. The best mi/kWh oh my R1T was 2.2. My S, which is a less aerodynamic body than the T, has the running boards and mudflaps, achieved a better mi/kWh at 2.24 which is more than my R1T.

 

[mkhuffman]

Ok, so let’s start from the beginning. It’s safe to say the T is more aerodynamic than the S because the T gets 347 in conserve mode versus the S 328. That is with the 21” wheels with aero caps inserted from Rivian.
This thread is about efficiency of the 20 inch wheels on AS tires compared to the 20 inch wheels on AT. I took it a step further and posted a couple of YouTube videos from engineering explained who nicely points out that the most efficient setup is the smallest diameter wheel on the same size tire. Thus, my claim that any 20 inch forged wheel on 275/60/20 is more efficient that the 21 setup from Rivian. His video explains it all.
So, when I got my S. I swapped the 22’s and put on the Rivian 20 inch wheels with 275/60/20 Pirelli AS 3. I also put on mudflaps and running boards from EVSportline. Now, my experience with my driving trips to Disney. The best mi/kWh oh my R1T was 2.2. My S, which is a less aerodynamic body than the T, has the running boards and mudflaps, achieved a better mi/kWh at 2.24 which is more than my R1T.

According to EPA figures, you are correct, but just barely:

They are practically the same. So the aerodynamic performance of each is practically the same.

Based on your numbers, you are getting the same efficiency with your R1T and your R1S. (2.2 vs. 2.24 is identical, IMO, because so many factors influence efficiency and .04 is noise.)

It is possible the AT rims with A/S tires are as efficient as the stock 21 wheel configuration, but I doubt it. Rivian designed the 21 rims with areo covers to be as aerodynamic as possible, and they are definitely more aerodynamic than the 20 inch rims. And Rivian specified the tires, which are likely low rolling resistance and more efficient than the aftermarket A/S people are trying out.

Less aerodynamic rims and higher rolling resistance tires means the wheel configuration on your R1S is less efficient than that on your R1T. Maybe not measurably less based on how you drive, but my guess it is 3-5% less at highway speeds. This correlates well with what people are seeing who have put the aftermarket areo covers on their 20 inch AT rims. https://www.rivianforums.com/forum/...r-rivian-r1t-r1s-20-all-terrain-wheels.13457/

 

[anthonysfl]

According to EPA figures, you are correct, but just barely:

They are practically the same. So the aerodynamic performance of each is practically the same.

Based on your numbers, you are getting the same efficiency with your R1T and your R1S. (2.2 vs. 2.24 is identical, IMO, because so many factors influence efficiency and .04 is noise.)

It is possible the AT rims with A/S tires are as efficient as the stock 21 wheel configuration, but I doubt it. Rivian designed the 21 rims with areo covers to be as aerodynamic as possible, and they are definitely more aerodynamic than the 20 inch rims. And Rivian specified the tires, which are likely low rolling resistance and more efficient than the aftermarket A/S people are trying out.

Less aerodynamic rims and higher rolling resistance tires means the wheel configuration on your R1S is less efficient than that on your R1T. Maybe not measurably less based on how you drive, but my guess it is 3-5% less at highway speeds. This correlates well with what people are seeing who have put the aftermarket areo covers on their 20 inch AT rims. https://www.rivianforums.com/forum/...r-rivian-r1t-r1s-20-all-terrain-wheels.13457/

I’m not sure why you are knocking a small data point that shows a case for people to put AS tires on their 20’s for efficiency. I just got the S and will continue to post data from my S that compares to my T because that’s the closest apple to apples comparison we have. Comparing mi/kWh to other peoples that drive different routes and live in different geographies means nothing. My worst efficiency on the Disney drive with my T was 1.94 mi/kWh. Wait for some more data.

Also not sure how you can assume something is the same that has a measurable black and white difference. The T’s 66 is greater than the S’s 65 highway mpge.
So what you’re saying is that my R1S, that is not as efficient on the highway as the T, with non ev tires, less aerodynamic wheels, running boards, mudflaps and the AC blasting because it’s Florida in August, that got a better mi/kWh number than my R1T with aero caps and minimal AC for Florida in February isn’t a positive data point?
Could you imagine a setup with a forged 20inch wheel on a 275/60/20 EV tuned tire with aero caps? Just because Rivian designed their most efficient setup with a 21 inch wheel doesn’t mean it’s truly the most efficient setup.





On my round trip 27 mile trip to work that is city driving. The highest I saw with my T was 2.84. My S so far I got 3.00 flat. So seeing a maximum of 5.6% increase in city driving to a break even on the highway is not measurable?

 

[mkhuffman]

I’m not sure why you are knocking a small data point that shows a case for people to put AS tires on their 20’s for efficiency. I just got the S and will continue to post data from my S that compares to my T because that’s the closest apple to apples comparison we have. Comparing mi/kWh to other peoples that drive different routes and live in different geographies means nothing. My worst efficiency on the Disney drive with my T was 1.94 mi/kWh. Wait for some more data.

Also not sure how you can assume something is the same that has a measurable black and white difference. The T’s 66 is greater than the S’s 65 highway mpge.
So what you’re saying is that my R1S, that is not as efficient on the highway as the T, with non ev tires, less aerodynamic wheels, running boards, mudflaps and the AC blasting because it’s Florida in August, that got a better mi/kWh number than my R1T with aero caps and minimal AC for Florida in February isn’t a positive data point?
Could you imagine a setup with a forged 20inch wheel on a 275/60/20 EV tuned tire with aero caps? Just because Rivian designed their most efficient setup with a 21 inch wheel doesn’t mean it’s truly the most efficient setup.





On my round trip 27 mile trip to work that is city driving. The highest I saw with my T was 2.84. My S so far I got 3.00 flat. So seeing a maximum of 5.6% increase in city driving to a break even on the highway is not measurable?

You are convinced your wheel configuration is more efficient than the stock 21 wheel configuration. I am not. However, I think it is possible they are close, and possibly the difference is difficult to measure, especially when you compare efficiency from February to efficiency in the summer.

But whatever, I am not going to convince you so we should just move on.

Just curious: do you still have the R1T? If so, you could swap the wheels between the S and the T and see what happens. That would be interesting.

 

[Zorg]

I’m not sure why you are knocking a small data point that shows a case for people to put AS tires on their 20’s for efficiency. I just got the S and will continue to post data from my S that compares to my T because that’s the closest apple to apples comparison we have. Comparing mi/kWh to other peoples that drive different routes and live in different geographies means nothing. My worst efficiency on the Disney drive with my T was 1.94 mi/kWh. Wait for some more data.

Also not sure how you can assume something is the same that has a measurable black and white difference. The T’s 66 is greater than the S’s 65 highway mpge.
So what you’re saying is that my R1S, that is not as efficient on the highway as the T, with non ev tires, less aerodynamic wheels, running boards, mudflaps and the AC blasting because it’s Florida in August, that got a better mi/kWh number than my R1T with aero caps and minimal AC for Florida in February isn’t a positive data point?
Could you imagine a setup with a forged 20inch wheel on a 275/60/20 EV tuned tire with aero caps? Just because Rivian designed their most efficient setup with a 21 inch wheel doesn’t mean it’s truly the most efficient setup.





On my round trip 27 mile trip to work that is city driving. The highest I saw with my T was 2.84. My S so far I got 3.00 flat. So seeing a maximum of 5.6% increase in city driving to a break even on the highway is not measurable?

You had me at hello.

Would be interesting to see what aero 20" wheels with AS tires would yield.

 

[mkhuffman]

You had me at hello.

Would be interesting to see what aero 20" wheels with AS tires would yield.

IMO it really depends on the rubber compound in the 21 stock tires. If they are designed for low rolling resistance, it will be hard to overcome that advantage with just aerodynamic improvements to the wheel. But maybe, at high speeds, it would. At low speeds, definitely not. Rolling resistance reduces efficiency at all speeds.

Edit: it is very frustrating to try to find a tire that has low rolling resistance. There is no standard. About all you can do is find one that says it is designed for low rolling resistance and EV use. But all the remaining tires can have significant differences and there is no way to tell.

However, if you see a A/S tire has excellent snow performance, it likely has poor rolling resistance. Unfortunately, they have not figured out how to make a low rolling resistance tire that is also good in the snow. The CrossClimate tire is an example of an excellent tire in all respects, except rolling resistance. You can read about Tesla drivers who saw significant efficiency decreases after putting them on.

 

[anthonysfl]

Here is more date for anyone considering the switch. These are pretty much the exact same routes to and from Orlando on the turnpike here in Florida, just different times of the year. Tried to get similar speed and distance.
My previous trips with R1T (on 21’s with Aero inserts on) numbers range from

• January leg home - 153.9mi, 72mph, 2.07mi/kWh, total 75kWh
• February to - 156.6mi, 70mph, 2.2mi/kWh, total 71 kWh
• February home - 155, 72, 1.94mi/kWh, total 79.9kWh

R1T first picture. Second in R1S on 20 AT brights with AS tires.

R1S 20 AT brights on AS 275/60/20 (thinks it’s on 22’s)
To Orlando - 157mi, 67mph, 2.24, 70.1
From Orlando - 148.4, 73mph, 2.25, 66

 

[EarlyAdptr]

Why is the Total Energy between the two trips SO different? 37.5 (R1T) vs 66 (R1S).

I'm new to all of this, so just trying to understand. The manual calculation of Efficiency for the second trip calculates correctly. When calculating the Efficiency for the first trip (R1T) I get an Efficiency of 4.10.

Confused?

 

[anthonysfl]

Why is the Total Energy between the two trips SO different? 37.5 (R1T) vs 66 (R1S).

I'm new to all of this, so just trying to understand. The manual calculation of Efficiency for the second trip calculates correctly. When calculating the Efficiency for the first trip (R1T) I get an Efficiency of 4.10.

Confused?

Rivian odometer had issues earlier this year. The February 2023 update fixed the number tracking. Just double the number, and you get 75 total.

 

[Riviot]

Here is more date for anyone considering the switch. These are pretty much the exact same routes to and from Orlando on the turnpike here in Florida, just different times of the year. Tried to get similar speed and distance.
My previous trips with R1T (on 21’s with Aero inserts on) numbers range from

• January leg home - 153.9mi, 72mph, 2.07mi/kWh, total 75kWh
• February to - 156.6mi, 70mph, 2.2mi/kWh, total 71 kWh
• February home - 155, 72, 1.94mi/kWh, total 79.9kWh

R1T first picture. Second in R1S on 20 AT brights with AS tires.

R1S 20 AT brights on AS 275/60/20 (thinks it’s on 22’s)
To Orlando - 157mi, 67mph, 2.24, 70.1
From Orlando - 148.4, 73mph, 2.25, 66

I think this is an apples to oranges-with-AS comparison. These are different vehicles with different aerodynamics, battery packs, and consumption rates. Cross-comparing wheels doesn't give you a delta of pre/post AS or 21 vs 20AS.

 

[anthonysfl]

I think this is an apples to oranges-with-AS comparison. These are different vehicles with different aerodynamics, battery packs, and consumption rates. Cross-comparing wheels doesn't give you a delta of pre/post AS or 21 vs 20AS.

As said before in this forum. The T is more aerodynamic than the S. Why else would it get 347 in conserve mode versus the 328 of the S on 21’s with the same battery back? So for my S to have better mi/kWh than my T has merit. Unless you or anyone else has both vehicles on different wheels, this is the best data so far. I’m working on finding someone with 21’s on an S for a range test.

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