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

[dfairris]

I know how difficult it is to "hold all else constant" in testing for statical difference. But, with growing numbers of comparative tests, something reasonably trustworthy genetally emerges, SO LONG AS TESTERS HAVE NO SKIN IN THE GAME. Who, among the various testers, should I trust and why?

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[cwq93r]

Please post publicly when there has been a fair efficiency/range comparison between the 20"s and 21"s. This is important for me. My order window is Sept/Oct. I make two 1000 mile trips a year and have opted, at this point, for the 21"s entirely for the range. I like the looks of the 20"s better.

I live on a dirt road and there may be times when I will take the R2 on a road that is rocky and rugged, but not often and only to get to an obscure hiking area. I am not an "off-roader." The 20" might.be preferable in this case.

If there is truly no decent range difference between the two, I want to change my current configuration immediately.

This should be a no-brainer in your situation. You should opt for the 20 inch wheels. At least that way you have a choice. If you don’t like the trail terrain wheels that the R2 comes with, then you can put on some all seasons later. You should still get better range with all seasons on the 20 inch wheels than the 21’s. The only real decision at this point is to decide on which ones look better to you. not perform better before OEM tire replacements are needed

 

[ksurfier]

I know how difficult it is to "hold all else constant" in testing for statical difference. But, with growing numbers of comparative tests, something reasonably trustworthy genetally emerges, SO LONG AS TESTERS HAVE NO SKIN IN THE GAME. Who, among the various testers, should I trust and why?

This should be a no-brainer in your situation. You should opt for the 20 inch wheels. At least that way you have a choice. If you don’t like the trail terrain wheels that the R2 comes with, then you can put on some all seasons later. You should still get better range with all seasons on the 20 inch wheels than the 21’s. The only real decision at this point is to decide on which ones look better to you. not perform better before OEM tire replacements are needed

Also, should the rumored/fable of the 21" advantage ever actually materialize, net effect is prob. only ~5 - 10 miles of extra range...really not significant at all....that may be the most fascinating part of this!

The absolute absurdity of this claim is peak nonsense: " is giving people bad information. I really hope people don't spend their hard-earned money based on the false claims in this thread."

 

[Thebandit]

Data don’t support that notion, unfortunately:

You give a man two numbers and two numbers only and he will extrapolate the universe.

 

[r2fb]

it's rumored to exist

Official EPA tests are not rumors.

 

[r2fb]

This should be a no-brainer in your situation. You should opt for the 20 inch wheels. At least that way you have a choice. If you don’t like the trail terrain wheels that the R2 comes with, then you can put on some all seasons later. You should still get better range with all seasons on the 20 inch wheels than the 21’s. The only real decision at this point is to decide on which ones look better to you. not perform better before OEM tire replacements are needed

Or instead of spending $1000 for shitty offroad tires that weigh 64 lbs each, get the 21's, then replace them with 20" Enkei XM6's wrapped in Michelin Primacy A/S tires that weigh 56 lbs each. Total cost: $2500, but you can sell your 21 wheel and tire combo to offset that and you'll have the best of both worlds and most likely much better range than either factory option.

 

[cwq93r]

Or instead of spending $1000 for shitty offroad tires that weigh 64 lbs each, get the 21's, then replace them with 20" Enkei XM6's wrapped in Michelin Primacy A/S tires that weigh 56 lbs each. Total cost: $2500, but you can sell your 21 wheel and tire combo to offset that and you'll have the best of both worlds and most likely much better range than either factory option.

Who would want to buy the 21” wheels?
Also Gjeebs has a video on YouTube where he replaced his factory wheel/tire combo with a lighter aftermarket wheel/tire combo on his Rivian, and received no efficiency gains at all.

 

[stewmander]

Official EPA tests are not rumors.

They're also not representative of real world conditions or drivers, which is why no one has gotten the claimed range. The closest test to the EPA cycle was Edmunds, and even then they were still 8% below EPA claims.

 

[r2fb]

Who would want to buy the 21” wheels?
Also Gjeebs has a video on YouTube where he replaced his factory wheel/tire combo with a lighter aftermarket wheel/tire combo on his Rivian, and received no efficiency gains at all.

R2 non-performance owners might be interested in the wheels. Actually went to watch that video. He went from 2.64 to 2.69 mi/kWh on a R1S and was praising the quietness, handling, comfort of the new combo. A meaningful improvement given that it's a much bigger and heavier car so the importance of tires is lesser comparatively.

 

[dfairris]

Thanks for the responses. I can see I reignited some of the vested interests in one or the other. But, there is light among the responses, too.

 

[ksurfier]

Tomorrow is a big day!

100,000 R2 miles on Roamer.

To celebrate, I’m dropping the GOAT thread — the biggest R2 data deep dive yet.

100,000 miles. A mountain of real-world data. Plenty of receipts.

Stay tuned.

 

[SuperFeisty]

I worry if any statisticians are reading this thread they're gonna have a heart attack. So many "conclusions" based on uncontrolled observations. The only reliable comparison would be to take 2 vehicles under the exact same controlled environment, each with the different wheel/tire package, and run them from 100% to 0%.

It's been over a decade since stats in college, but I believe you're speaking as to level of evidence. It sounds like you're saying this situation should be treated as a randomized control study which is strong data. A concern here is even if the EPA tried to control variables, what is each group's sample size? An RCT to "prove" a 7% difference with adequate power would be impossible for the EPA.

However, in statistics increasing sample size (almost 100,000 miles driven) leads to often stronger evidence as well. Systematic reviews and metanalyses carry more statistical weight than even an adequately powered RCT. The greater the sample size, the less individual deviations matter, so arguments about 21' wheel drivers being more aggressive or tires not being broken in become less and less effective. If speaking as to efficiency, I believe the null hypothesis is the 21s and 20s are not different, and so far the data cannot disprove this.

 

[mclark2112]

This should be a no-brainer in your situation. You should opt for the 20 inch wheels. At least that way you have a choice. If you don’t like the trail terrain wheels that the R2 comes with, then you can put on some all seasons later. You should still get better range with all seasons on the 20 inch wheels than the 21’s. The only real decision at this point is to decide on which ones look better to you. not perform better before OEM tire replacements are needed

And if you choose not to decide, you still have made a choice.

Sorry, saw two Rush shows in Philly, everything is a song lyric this week

 

[Husky]

After looking at 20" wheels that will fit the R2 on Tire Rack, I've got my plan.
I've already ordered my R2 with the 21" wheels. If, after the tires are due for replacement, I feel like switching to 20" wheels and tires, I can buy a nice set of Enkie wheels for $1200 to put my new tires on. These wheels are about fifteen pounds apiece lighter than the factory 20" wheel!
True, they are not forged, but will do just fine for my driving.
So for almost the same price as the 20" option, I can end up with two sets of wheels, and I won't be stuck driving on AT tires for 20k-30k miles. Win-win.

 

[dfairris]

Received my notification to order this morning. I had a Sept/Oct window. Ordered the 20" wheels based on the discussion and evidence in this thread. Thanks, folks. Hope the data dump tomorrow doesn't throw all of the prior analyses into question.

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