20in wheel worse range even with all season tires?

[usulio]

If Rivian could improve EPA range with a smaller wheel, they would do it. Right?

Eh, I suspect that aesthetics is a big part of Rivian's size decisions (otherwise the tires would be smaller than 32" diameter, for one thing).

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[mkhuffman]

Eh, I suspect that aesthetics is a big part of Rivian's size decisions (otherwise the tires would be smaller than 32" diameter, for one thing).

Same with performance. They could use less powerful motors and a smaller, lighter battery, and gain efficiency. And a smaller cabin with a shape like a jellybean would also be more efficient.

So?

Bigger can be more efficient. Smaller can also. Size isn't the deciding factor.

 

[Megaman0025]

Yeah bc they put off road tires on the 20" rim. Put the same tire that's on the 22" rim on the 20" rim and it is more efficient than the 22". Smaller rim is always "better" with the same tire and design.

At highway speeds it’s almost meaningless because the weight penalty of a larger wheel is gone once the wheel is spinning - the aero of the wheel will matter the most on the highway, assuming the tires are the same.

 

[mkhuffman]

At highway speeds it’s almost meaningless because the weight penalty of a larger wheel is gone once the wheel is spinning - the aero of the wheel will matter the most on the highway, assuming the tires are the same.

 

[CrazyOne]

We just did a road trip on I-90 and the concrete on it was in terrible condition. The noise and vibration transmitted to car was unbearable for me. It was on this drive that I decided to switch to 20 inch wheels. I don't care if I have to stop an extra time or if charging takes 10 more minutes. I will accept that hit a few times in year.

For those not familiar, it goes over a pass, everyone uses studded tires on concrete and the surface is the worst I have ever driven outside of wheel eating potholes I experienced in Ohio.

 

[iamnid]

 

[CD1973]

Standard AWD LR gets 330 miles on 19s. Anyone know why 19s are not an option on higher trim levels?

 

[Zoidz]

I just read through this entire thread.

I usually dive in pretty deep on stuff like this (math and science, etc.) but I decided years ago that for me, with all the unknown variables, trying to figure out optimium wheel/tire configuration for mileage efficiency isn't worth it. To throw a wrench in everyone's exacting calculations, is anyone factoring in that your climate/weather conditions also affect your efficiency, therefore tire compound is another unknown variable? The optimum tire might change depending on if you are in Pacific NW vs Florida?

I originally ordered the 20" rims / ATs to give me plenty of replacement options when the time came. I bought the popular 20" Michellin LTX MS/2 a few weeks ago, deciding that my highway driving was more important than my off road driving, and the Michelins would be "good enough" for my beach and trail driving. I'm a firm believer that knowing how to drive in sand and light dirt/mud is more important than the tire tread. I've seen a few jacked up, knobby tired F150s buried to the axle, lol.

Getting to the point, my long term efficiency (measured as an 8000+ mile trip A) on the 20" Scorpions was 2.12. With 600 miles on the LTX, the efficiency is 2.05. That's insignificant as far as I care. The noise and treadwear are much more important than .07 difference in efficiency. Over the longer haul that efficiency could go up or down, but not much.

So, is all this math and science worth it considering all the unknown variables that you can't factor in?

 

[mkhuffman]

I just read through this entire thread.

I usually dive in pretty deep on stuff like this (math and science, etc.) but I decided years ago that for me, with all the unknown variables, trying to figure out optimium wheel/tire configuration for mileage efficiency isn't worth it. To throw a wrench in everyone's exacting calculations, is anyone factoring in that your climate/weather conditions also affect your efficiency, therefore tire compound is another unknown variable? The optimum tire might change depending on if you are in Pacific NW vs Florida?

I originally ordered the 20" rims / ATs to give me plenty of replacement options when the time came. I bought the popular 20" Michellin LTX MS/2 a few weeks ago, deciding that my highway driving was more important than my off road driving, and the Michelins would be "good enough" for my beach and trail driving. I'm a firm believer that knowing how to drive in sand and light dirt/mud is more important than the tire tread. I've seen a few jacked up, knobby tired F150s buried to the axle, lol.

Getting to the point, my long term efficiency (measured as an 8000+ mile trip A) on the 20" Scorpions was 2.12. With 600 miles on the LTX, the efficiency is 2.05. That's insignificant as far as I care. The noise and treadwear are much more important than .07 difference in efficiency. Over the longer haul that efficiency could go up or down, but not much.

So, is all this math and science worth it considering all the unknown variables that you can't factor in?

100%.

There are so, so many variables that impact efficiency, and thinking you can outsmart Rivian engineers is priceless. I wonder how many hours they spent coming up with the most efficient rim and rubber? They definitely didn't just weigh the tire. LOL.

I have always believed you might be able to match OEM efficiency with the right combination of rims and tires, but I seriously doubt anyone can beat the most efficient OEM wheels. Sure you can improve efficiency by replacing the AT tires with low rolling resistance road tires, since road efficiency isn't the highest priority when picking AT tires. Other than that, it's a waste of time IMO.

If the top priority is efficiency, stick with the OEM setup.

 

[velopod]

I just read through this entire thread.

I usually dive in pretty deep on stuff like this (math and science, etc.) but I decided years ago that for me, with all the unknown variables, trying to figure out optimium wheel/tire configuration for mileage efficiency isn't worth it. To throw a wrench in everyone's exacting calculations, is anyone factoring in that your climate/weather conditions also affect your efficiency, therefore tire compound is another unknown variable? The optimum tire might change depending on if you are in Pacific NW vs Florida?

I originally ordered the 20" rims / ATs to give me plenty of replacement options when the time came. I bought the popular 20" Michellin LTX MS/2 a few weeks ago, deciding that my highway driving was more important than my off road driving, and the Michelins would be "good enough" for my beach and trail driving. I'm a firm believer that knowing how to drive in sand and light dirt/mud is more important than the tire tread. I've seen a few jacked up, knobby tired F150s buried to the axle, lol.

Getting to the point, my long term efficiency (measured as an 8000+ mile trip A) on the 20" Scorpions was 2.12. With 600 miles on the LTX, the efficiency is 2.05. That's insignificant as far as I care. The noise and treadwear are much more important than .07 difference in efficiency. Over the longer haul that efficiency could go up or down, but not much.

So, is all this math and science worth it considering all the unknown variables that you can't factor in?

Me too (read this thread - more for entertainment since I'm a tire nerd). Love your post. First post for me!

I currently pilot a Porsche Cayenne Turbo with HUGE 315/30/22 rears. What you really learn with extreme tire examples like this is that tire COMPOUND matters a ton with temperature (as you mentioned). The Michelin Pilot Sports are worthless on perfectly dry roads if under 40 degrees F. I run Pirelli Scorpion WINTER tires in the colder months (same size) more for the compound then "traction" as I really don't get much snow around here and the Cayenne Turbo is my daily driver. I run even softer tires on an old Boxter I have for fun and you should see how soft a motorcycle tire is for grip!

Since most people on this thread appear to be mostly interested in efficiency (as defined by them as miles/charge it appears), they are not considering all the variables that a team of Rivian engineers do. You are the first I noted with the ambient temp variable in there to further blow people's minds ... Then you could add aftermarket, wrong offset sticking that wheel out just 5 mm, etc. LOL.

In short, people need to be honest in what they value most. I run 2 sets of tires in most of my vehicles as I dislike "all season" tires since they try to blend traction, longevity, etc. for convenience. I prefer (at least on a Turbo Cayenne) max traction/handling for summers, then winters when needed. I'll take the extra cost for this and inconvenience of changing out. I don't care about perceived comfort, etc.

Wife's SUV - completely different animal where comfort and convenience are more priorities, hence her all season Michelins

To throw another wrench in here, how about an aftermarket company makes a rim insert to put on for long highway trips on the 20" Rivian rims that people seem to like to offset the range penalty. Many other manufacturers do this (Lucid, Tesla). Would "fix" many issues (other than cosmetics) or cost, tire availability, etc for many here. The better Rivian rims are very nice designs (EV or otherwise), color and are FORGED (I think) so would be a shame though

 

[mkhuffman]

...
To throw another wrench in here, how about an aftermarket company makes a rim insert to put on for long highway trips on the 20" Rivian rims that people seem to like to offset the range penalty. Many other manufacturers do this (Lucid, Tesla). Would "fix" many issues (other than cosmetics) or cost, tire availability, etc for many here. The better Rivian rims are very nice designs (EV or otherwise), color and are FORGED (I think) so would be a shame though

An aftermarket company did just that for the original 20" OEM wheels. And from reports on this forum, the efficiency improvement due to aerodynamics was not obvious. Air currents are hard to predict, and sometimes something that looks more aerodynamic isn't. That said, I personally think the covers helped and maybe improved efficiency a percent or two at highway speeds. Maybe. For most people, the improvement was too small to notice.

Rivian puts covers on the 22" Range wheels. I thought about replacing my 22" Sport wheels with those since they are more efficient on the highway. I remember some reports from Rivian "engineers" that the covers add around 10 miles of range. Not much. (Those reports are just hearsay, but it sounds reasonable.) It might be better than that at 80 mph, though.

One of my favorite aftermarket wheels has screw holes for mounting a aero cover. As far as I know, they have yet to produce the cover. I suppose you could 3D print your own:
MPP Rivian Wheels - Introducing "Mega Terra"

 

[velopod]

Yes, acutely aware of wind variables and how they interact from bike racing years (running a solid rear disc for time trials). Even small changing wind angles makes a huge difference on aero drag. But the faster you go (even from 25 to 30 mph say on a bike) makes a big diff. As tests show, 80 mph (a more typical, modern highway travel speed), they probably would help a fair bit. 10 miles sounds reasonable and can make the difference I'd be interested in.

I wouldn't be interested in saving "money", but if I could save TIME for a long trip to make it or one less charging stop, might be worth it.

 

[mkhuffman]

Yes, acutely aware of wind variables and how they interact from bike racing years (running a solid rear disc for time trials). Even small changing wind angles makes a huge difference on aero drag. But the faster you go (even from 25 to 30 mph say on a bike) makes a big diff. As tests show, 80 mph (a more typical, modern highway travel speed), they probably would help a fair bit. 10 miles sounds reasonable and can make the difference I'd be interested in.

I wouldn't be interested in saving "money", but if I could save TIME for a long trip to make it or one less charging stop, might be worth it.

When I upgrade my Gen2 to a Gen3 with 180 kWh pack and 800V charging (LOL) I plan to order it with the Range wheels. I agree with you and want the longest range possible on the highway.

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