20in wheel worse range even with all season tires?

[tivoboy]

Exactly. Many think it's a simple choice. But what I'm mulling over is how much highway driving will I do? I'm beginning to think it's going to be a lot. So the 21 inch tires are a better choice for me than the all-terrain 20s. The 21s are 55s, while the 20s are 60s. So doesn't that mean they are wider? So maybe they're heavier because they have more rubber on the road, not to mention bigger walls.

I think for most the majority of driving is going to be ON some type of ROAD.. even a dirt road for limited off roading is going to be fine with the 21” and AS..of course snow, heavy rain, mud, well that changes it for sure.

But the choice to move to the 20” with AT, several ppl have said - well I’ll take off the AT, and put on AS tires (several more choices for sure), for the majority of the time while on highway or regular day to day driving.. and when I need the AT I’ll put them back on, etc.. that’s quite a pain overall. Probably something like at least $100 for each on an off (so $200)

Not to mention to have that scenario it costs $1000 more for the 20” AT wheels, (plus tax), PLUS at least another ~ $900-1000 for a quality 20” AS tire to put on them, plus the $100 to mount. So we’re at $2100 to have this option..

Overall it’s not too crazy high from a price standpoint ~ $2100 Plus tax to have AS tires on the 21” and keep the AT tires when winter in some areas, or adventure off roading.. but It’s still a pretty decent nut.

I’d be interested in what other quality aftermarket AT wheels one could get with AT tires, how much is that type of combination? $3000? $5000? And are the Rivian 20” AT wheels at the high end of the quality / capability range?

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[Tony S]

Exactly. Many think it's a simple choice. But what I'm mulling over is how much highway driving will I do? I'm beginning to think it's going to be a lot. So the 21 inch tires are a better choice for me than the all-terrain 20s. The 21s are 55s, while the 20s are 60s. So doesn't that mean they are wider? So maybe they're heavier because they have more rubber on the road, not to mention bigger walls.

They are both 255 mm wide …. Same patch width on the ground.

 

[mkhuffman]

I think for most the majority of driving is going to be ON some type of ROAD.. even a dirt road for limited off roading is going to be fine with the 21” and AS..of course snow, heavy rain, mud, well that changes it for sure.

But the choice to move to the 20” with AT, several ppl have said - well I’ll take off the AT, and put on AS tires (several more choices for sure), for the majority of the time while on highway or regular day to day driving.. and when I need the AT I’ll put them back on, etc.. that’s quite a pain overall. Probably something like at least $100 for each on an off (so $200)

Not to mention to have that scenario it costs $1000 more for the 20” AT wheels, (plus tax), PLUS at least another ~ $900-1000 for a quality 20” AS tire to put on them, plus the $100 to mount. So we’re at $2100 to have this option..

Overall it’s not too crazy high from a price standpoint ~ $2100 Plus tax to have AS tires on the 21” and keep the AT tires when winter in some areas, or adventure off roading.. but It’s still a pretty decent nut.

I’d be interested in what other quality aftermarket AT wheels one could get with AT tires, how much is that type of combination? $3000? $5000? And are the Rivian 20” AT wheels at the high end of the quality / capability range?

Heads up that it looks like Tire Rack only has one AS tire in 255/60 R20 that might improve range, maybe even approaching the 21" setup. It is a Land Rover OEM replacement.

https://www.tirerack.com/tires/Tire...&rearRatio=40&rearDiameter=17&performance=ALL

My guess is the OEM 21s are more efficient. So if road efficiency is your top priority, you should go with the 21s. IMO, of course.

 

[dcdttu]

The R2 wheels may be different sizes, but each wheel/tire combination is the same 32" total diameter, no matter which wheel you pick. This was done to minimize engineering challenges with different sized tire/wheel combinations.

19" wheels: 32" diameter
20" wheels: 32" diameter
21" wheelsL 32" diameter

20" wheels on AS tires should be similar to 21" wheels with AS tires, as long as the efficiency (rolling resistance) of the tires is similar. There's also tire width, which can play a role. I'm not sure if the 20" tires are wider or narrower than the 21" option.

 

[mferring]

The R2 wheels may be different sizes, but each wheel/tire combination is the same 32" total diameter, no matter which wheel you pick. This was done to minimize engineering challenges with different sized tire/wheel combinations.

19" wheels: 32" diameter
20" wheels: 32" diameter
21" wheelsL 32" diameter

Heads up that it looks like Tire Rack only has one AS tire in 255/60 R20 that might improve range, maybe even approaching the 21" setup. It is a Land Rover OEM replacement.

https://www.tirerack.com/tires/Tire...&rearRatio=40&rearDiameter=17&performance=ALL

My guess is the OEM 21s are more efficient. So if road efficiency is your top priority, you should go with the 21s. IMO, of course.

My concern is that the only tire listed at Tire rack for 255/55/21 is the OEM Pirelli Scorpion with no mileage warranty at all. There are no other choices.

At least for the 255/60/20 size there are a number of choices such as the Michelin Defender with a 75K 6yr warranty.

I know people say that the tire manufacturers will of course build more 255/55/21 tires after the R2 comes out. I am not one of those with great faith in this prediction......

Also, as a first time EV buyer, I know that EV's tend to chew through tires faster than non EVs. I like the idea of having a 75K warranty where Michelin has to give me a big rebate on my next tires if I don't come close to 75K within 6 yrs.....which I am sure I will not.

 

[emroch]

The R2 wheels may be different sizes, but each wheel/tire combination is the same 32" total diameter, no matter which wheel you pick. This was done to minimize engineering challenges with different sized tire/wheel combinations.

19" wheels: 32" diameter
20" wheels: 32" diameter
21" wheelsL 32" diameter

20" wheels on AS tires should be similar to 21" wheels with AS tires, as long as the efficiency (rolling resistance) of the tires is similar. There's also tire width, which can play a role. I'm not sure if the 20" tires are wider or narrower than the 21" option.

All R2 tires are the same width (and diameter, as you mentioned): https://www.rivianforums.com/forum/...s-width-offset-hub-bore-size-19-and-20.56973/

All are 255mm wide, with various aspect ratios to keep the OD at ~32" (both the ratio and the OD could be slightly rounded, so the math doesn't always come out exact)

19" - 65%
20" - 60%
21" - 55%

The biggest difference will be tread pattern/"knobbiness" and rubber compound. These will affect the rolling resistance and will play a bigger role than the slight weight differences.

 

[mkhuffman]

My concern is that the only tire listed at Tire rack for 255/55/21 is the OEM Pirelli Scorpion with no mileage warranty at all. There are no other choices.

At least for the 255/60/20 size there are a number of choices such as the Michelin Defender with a 75K 6yr warranty.

I know people say that the tire manufacturers will of course build more 255/55/21 tires after the R2 comes out. I am not one of those with great faith in this prediction......

Also, as a first time EV buyer, I know that EV's tend to chew through tires faster than non EVs. I like the idea of having a 75K warranty where Michelin has to give me a big rebate on my next tires if I don't come close to 75K within 6 yrs.....which I am sure I will not.

I guess you have to decide which is more important - tread warranty or efficiency. Those Michelin tires you referenced are unlikely to be more efficient than the OEM 20" tires.

I can say that while the OEM 22s on my R1T are expensive, they are great tires from a performance and efficiency perspective. But I will be lucky to get 30k out of them. I am OK with that trade off.

 

[mkg3]

...I know people say that the tire manufacturers will of course build more 255/55/21 tires after the R2 comes out. I am not one of those with great faith in this prediction......

Also, as a first time EV buyer, I know that EV's tend to chew through tires faster than non EVs. I like the idea of having a 75K warranty where Michelin has to give me a big rebate on my next tires if I don't come close to 75K within 6 yrs.....which I am sure I will not.

What makes you believe that tire mfg will not bring out other 255/55/21? Is there real basis to your assumptions or just a gut feeling?

We had this exact discussion for the R1 tire size 275/50/22. While the choices are not significant, there are options from multiple tire makers.

Also, it's flawed to assume all tires wear faster with EVs. The answer is it depends. An example is softer tires going to wear faster than harder tires, regardless if its EV or ICE.

I am used to replacing tires on all of my vehicles around 30k miles, regardless if it's an EV or ICE, which I still own both kinds. My R1S currently is riding on the Michelin Defender LTX M/S2 for 26k miles and still have about 50% tread life left. Frankly, I wish they would wear more as the Defender is a harder tires than I like and am used to. It would be silly to replace them when they are still perfectly fine.

Take a moment and look at the designed temperature and hardness. With a heavier vehicle, the harder tire will last longer, albeit will not handle like a softer, higher temperature tires.

So if I was making the choice, I would not hesitate on the 21", if that is what I wanted. The worst case is you replace the wheels to match the tire options. I prefer forged wheels anyways (lighter unsprung mass).

 

[Zathras]

They are both 255 mm wide …. Same patch width on the ground.

You're right, they are 255 60R20 and 255 55R21. Got them mixed up on stats.

 

[FlyingPilot2012]

I guess you have to decide which is more important - tread warranty or efficiency. Those Michelin tires you referenced are unlikely to be more efficient than the OEM 20" tires.

I can say that while the OEM 22s on my R1T are expensive, they are great tires from a performance and efficiency perspective. But I will be lucky to get 30k out of them. I am OK with that trade off.

The Michelin Defenders are all season tires. They will almost certainly be more efficient than the all terrain tires that come with the OEM 20" wheels, but probably not as much as the 21" OEM tires.

If overall cost is a concern, range is only part of the equation. Consider a $450 tire that brings 10% better range but only lasts 30k miles vs a $350 tire that lasts 60k. Over the course of 120k, that's $7200 in tires vs $2800. That significant increase in tire cost probably cancels out any savings from that 10% range boost.

So I'd pick the tire that lasts closer to 60k.

Of course, ride quality, noise, grip, etc. are all factors too.

Just my two cents.

 

[mkhuffman]

The Michelin Defenders are all season tires. They will almost certainly be more efficient than the all terrain tires that come with the OEM 20" wheels, but probably not as much as the 21" OEM tires.

If overall cost is a concern, range is only part of the equation. Consider a $450 tire that brings 10% better range but only lasts 30k miles vs a $350 tire that lasts 60k. Over the course of 120k, that's $7200 in tires vs $2800. That significant increase in tire cost probably cancels out any savings from that 10% range boost.

So I'd pick the tire that lasts closer to 60k.

Of course, ride quality, noise, grip, etc. are all factors too.

Just my two cents.

It is a guessing game we are playing right now.

My guess is the AT tires (that are not really AT tires, they are more like AS tires actually - look at the tread) are very efficient and designed for low rolling resistance. The Michelin Defenders are not designed for low rolling resistance. Just because they are AS does not mean they will be more efficient.

The thing is, will you roll the dice and spend $1500 + shipping and installation to find out if you are right or not?

The Rivian specific "AT" tires are not really AT tires. They are highway tires with some off-road capable enhancements. (And, BTW, it looks like Tire Rack is selling them for a lot less than $450 each.)

The tread design is not much different than the AS Defenders:

A real AT tire looks more like this:

Note: I realize that sometimes the Tire Rack pictures are not accurate. So if that is the case, I apologize.

 

[ksurfier]

The two tire camps explained:
20” - There are 25 million tire options
21” - The single option is 0.000001 % more efficient

 

[LevelHeaded]

The two tire camps explained:
20” - There are 25 million tire options
21” - The single option is 0.000001 % more efficient

Exactly. Buy whatever 20s your trim offers, and swap to a tire you prefer, depending on what you’re targeting, either right away or at the end of the factory tire lifespan. Easy imo!

 

[Raptor911]

Interesting thread. I plan to buy aftermarket 20" wheels and run Michelin Pilot Sport All Season 4 in 255/55/20. This tire does not come in 255/60/20 (R2 OEM 20" tire size ). So

 

[mkhuffman]

Interesting thread. I plan to buy aftermarket 20" wheels and run Michelin Pilot Sport All Season 4 in 255/55/20. This tire does not come in 255/60/20 (R2 OEM 20" tire size ). So

Efficiency readings will be off also, because the truck will think you have traveled farther than you really have. In theory, when the truck shows you 3.0 mi/kWh, your actual efficiency will be 3.0 * 0.969 = 2.91 mi/kWh. That is what would annoy me the most.

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