Growing efficiency Gap: R2 w/ 21" vs. 20" tire sets

[mkhuffman]

All good. Statistically there are always a few people who are completely in the wrong (I kid, I kid).

-Rich

Rivian has done controlled testing and without a doubt the 21" R2 wheel is the most efficient. It is ridiculous that there are people who think they are smarter than Rivian just because of some data in RR. And it is beyond ridiculous we are even debating it.

You will NOT get the best efficiency with the 20" AT wheels. Rivian isn't lying.

If anyone makes a decision to order a R2 with 20s because of this thread, don't be surprised when you never even get close to the efficiency possible with the 21s.

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[Budman]

Rivian has done controlled testing and without a doubt the 21" R2 wheel is the most efficient. It is ridiculous that there are people who think they are smarter than Rivian just because of some data in RR. And it is beyond ridiculous we are even debating it.

You will NOT get the best efficiency with the 20" AT wheels. Rivian isn't lying.

If anyone makes a decision to order a R2 with 20s because of this thread, don't be surprised when you never even get close to the efficiency possible with the 21s.

What he said. AT will not be more efficient.

 

[tivoboy]

It does seem silly to debate it.. the EPA numbers that Rivian gave out aside, do we REALLY think they didn’t do enough testing that they were still comfortable putting it on their website and PR documents that that 21” should have 330 EPA rated range and the 20” should have a ~ 307 rated range.?

If they had done ANY testing and found that the 20” was somehow more efficient, they would certainly put the 20” HIgHER than the 21”. And that is about a 10% difference that they note.. if we’re truly to believe that the 20”: are at least 7% MORE efficient from these reports, then Rivian didn’t just get it wrong by 10%, they got it wrong by 17%.

 

[DJFrerichs]

Rivian has done controlled testing and without a doubt the 21" R2 wheel is the most efficient. It is ridiculous that there are people who think they are smarter than Rivian just because of some data in RR. And it is beyond ridiculous we are even debating it.

You will NOT get the best efficiency with the 20" AT wheels. Rivian isn't lying.

If anyone makes a decision to order a R2 with 20s because of this thread, don't be surprised when you never even get close to the efficiency possible with the 21s.

THIS THIS THIS THIS THIS.....

 

[richpike]

This is not about stating someone is right or wrong here as we should all be helping each other in support of the brand and what it provides. This is more about making sure people area aware of the information in front of them and if it is fully reliable or not. This kind of miss informative data can cost ya money in the long run if miss understood on how it is calculated and if it is factual in comparison.

But it’s not “miss information”. Statistically, the sample size is getting large enough that the unique circumstances average out. I’ll see if Chad (RivianRoamer) can do a bar graph of the efficiency for each user by tire. My guess is it’s already a rough Gaussian shape.

-Rich

 

[richpike]

Rivian has done controlled testing and without a doubt the 21" R2 wheel is the most efficient. It is ridiculous that there are people who think they are smarter than Rivian just because of some data in RR. And it is beyond ridiculous we are even debating it.

You will NOT get the best efficiency with the 20" AT wheels. Rivian isn't lying.

If anyone makes a decision to order a R2 with 20s because of this thread, don't be surprised when you never even get close to the efficiency possible with the 21s.

Except, and hear me out (and read what I wrote before), what if the 21s they're using right now have an issue? I get your point - AT tires should not be more efficient. But the data so far shows they are - so maybe, just maybe, there is an issue with the batch of Pirelli's Rivian has? Or there was something different in the way the EPA test was done? Or? We've seen Rivian change to different revisions of multiple parts (early subframe, etc) because they weren't performing as they expected. The 21 is a tire only used by Rivian at this point. It's not out of the realm of possibility that something is off there.

In the end, the data (so far) does not support the 21s being more efficient by any meaningful amount.

-Rich

 

[Dennisis]

FWIW I’ve read enough to convince me to order with the 20’s. I’ve never liked the larger wheels and I can always put more efficient tires on my 20’s when/if the mood strikes me, not so much with the 21’s.

 

[ksurfier]

Except, and hear me out (and read what I wrote before), what if the 21s they're using right now have an issue? I get your point - AT tires should not be more efficient. But the data so far shows they are - so maybe, just maybe, there is an issue with the batch of Pirelli's Rivian has? Or there was something different in the way the EPA test was done? Or? We've seen Rivian change to different revisions of multiple parts (early subframe, etc) because they weren't performing as they expected. The 21 is a tire only used by Rivian at this point. It's not out of the realm of possibility that something is off there.

In the end, the data (so far) does not support the 21s being more efficient by any meaningful amount.

-Rich

We cannot yet statistically demonstrate that the 20” is more efficient. But the accumulating evidence is becoming increasingly inconsistent with the hypothesis that the 21” provides anything close to Rivian’s expected ~7% real-world efficiency advantage.

 

[Mos Eisley]

Except for the fact that we have 250+ mile drives that seem to suggest essentially the same efficiency, so this suggests that there isn’t a clear winner 20 vs 21 inch…

On different roads, weather, drivers….

 

[Thebandit]

But it’s not “miss information”. Statistically, the sample size is getting large enough that the unique circumstances average out.

This is absolute nonsense. I agree that the trend so far looks like there isn't a significant difference, but in terms of mathematics and statistics this is an absolutely incorrect and nonsensical claim. Most of these tires are well within their break in period and they could have dramatically better efficiency after the first 1000 miles. The people who spend the extra money for the AT tires are likely to have significantly different driving habits than the people taking the stock AS tires.

There are just a million variables that can significantly skew these results that are completely unaccounted for. You have absolutely no basis to make this claim.

 

[ksurfier]

What he said. AT will not be more efficient.

But is the 21” really ~10% more efficient….that’s the question we are trying to answer. Even cherry-picking the best highway result for each tire gives the 21” only about a 3% advantage—less than half Rivian’s predicted ~7.5%. Across the broader owner dataset, that small advantage disappears and currently reverses in favor of the 20”.

 

[richpike]

This is absolute nonsense. I agree that the trend so far looks like there isn't a significant difference, but in terms of mathematics and statistics this is an absolutely incorrect and nonsensical claim. Most of these tires are well within their break in period. The people who spend the extra money for the AT tires are likely to have significantly different driving habits than the people taking the stock AS tires.

There are just a million variables that can significantly skew these results that are completely unaccounted for. You have absolutely no basis to make this claim.

Lets see - I asked Chad if he can do a graphical distribution of the 30+ users so far (and their mi/kWh) for each tire. My guess is it's already a rough guassian shape - which shows the data is aligning. Would 3,000 users be best? Sure. But statistically, 30 users with 15-20k miles overall for each set is actually a pretty large sample.

-Rich

 

[windshieldfarmer]

A range test with the two respective tires in a controlled environment is the only way to validate the outcome…which is what I thought the EPA test accomplished. Absent another test of some type that controls for environmental differences, the best we can continue to do is watch other data such as that provided Rivian Tracker to see if the gap ultimately reverses. Candidly there is enough anecdotal evidence to suggest the differences in range between the respective tires is less than originally thought in real world applications.

 

[mkhuffman]

Except, and hear me out (and read what I wrote before), what if the 21s they're using right now have an issue? I get your point - AT tires should not be more efficient. But the data so far shows they are - so maybe, just maybe, there is an issue with the batch of Pirelli's Rivian has? Or there was something different in the way the EPA test was done? Or? We've seen Rivian change to different revisions of multiple parts (early subframe, etc) because they weren't performing as they expected. The 21 is a tire only used by Rivian at this point. It's not out of the realm of possibility that something is off there.

In the end, the data (so far) does not support the 21s being more efficient by any meaningful amount.

-Rich

The data is not controlled test data, so it does NOT provide any evidence the 20s are more efficient. None. It just means for some reason the people with 20s are driving more efficiently. We have no idea why.

 

[richpike]

The data is not controlled test data, so it does NOT provide any evidence the 20s are more efficient. None. It just means for some reason the people with 20s are driving more efficiently. We have no idea why.

With enough samples it doesn't need to be a controlled test set...

-Rich

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