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ksurfier

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There are 8 options and until there's an actual test with data it's safe to assume these tires are not going to be as efficient as 35-40# AS tires...if I was getting an AT tire then I'd aim for at least 9.4" width...only 1 option below would work and it's basically 60#...I would also not get a 44 psi tire - even if it's 100% fine.
Size (Nitto Recon Grappler AT)WeightDiameterMaxWidth
275/60R20 | 116S46#33"50 psi9.1"
305/55R20 | 116S51#33"44 psi10.5"
LT275/60R20 | 123/120S55#33"80 psi9.3"
LT285/60R20 | 125/122S59#33.5"80 psi9.8"
LT295/55R20 | 123/120S59#33"80 psi10.6"
275/65R20 | 116T47#34"44 psi8.8"
LT275/65R20 | 126/123S57#34"80 psi9"
315/60R20 | 116S57#35"44 psi10.5"
 

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So why can't you use at 44psi?
 

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ksurfier

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There's a very long answer that I'm not capable/interested in posting but here's a shortish version:
Below 50 psi is Standard Load tire territory, SLs typically have a lighterweight construction and aren't suitable for heavier vehicles (it's one thing to run a SL tire on a Tacoma that's 4k pounds, but the R1S fully loaded is 8.5k pounds). SL tires aren't suitable for towing either (maybe super light towing is fine). For heavy loads/towing/offroading it's important to have the tires reinforcement where it matters most (sidewall/steel belts/bead/tread/plies(1,2,3...so on)). Big part is how tire dissipates heat at speed (the second letter in 800 A'A') A = Speed > 115 MPH, B = Speed 100-115, C = 85-100. This tire has 3 things going against it for holding up and not wearing out quickly:
UTQG is 600 so it will wear faster than the OEM Pirelli (640)
Speed rating (118 mph) is lower than OEM Pirelli (130 mph)
Tread compound is softer than the OEM Pirelli (EV rated)

Clearly the tire is fine to use, it meets the load requirements, but are there better tires out there that likely meet more requirements for a heavy SUV/Truck, certainly (and they will easily get 30,000 miles instead of ~15,000):
Firestone Destination X/T - 51# 285/60R20 (33.5" Diameter and 9.9" wide)
General Grabber A/TX - 50# 275/60R20 (33.0" Diameter and 9.6" wide)
 

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Clearly the tire is fine to use, it meets the load requirements, but are there better tires out there that likely meet more requirements for a heavy SUV/Truck, certainly (and they will easily get 30,000 miles instead of ~15,000):
I know the 15k/30k is a rough estimate, but let's continue that napkin math a little.

With my home electricity rates around 0.14c/kWh it cost me ~$70/1000 miles if I round off to 2 mi/kWh efficiency (which I have exceeded over 27k miles now). So ~$1050 for 15k miles. So getting the 20% more efficient SL's would save me around $200 over those 15k miles, or $400 over 30k miles. I either missed it or the cost of the tire wasn't included in the thread, but pretty simple math tells me buying 2 sets vs 1 set of tires over 30k miles is going to be a more expensive option.

Of course there are tons of variables in costs of charging, how you want to/need to use the truck, your own cabin noise tolerance, and how important the look of the tire is to someone. But I'm always impressed with the level of obsession generated by an efficiency number that a lot of us can fall into without stopping to do an actual cost comparison. I have been plenty guilty of that at times.
 

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There are 8 options and until there's an actual test with data it's safe to assume these tires are not going to be as efficient as 35-40# AS tires...if I was getting an AT tire then I'd aim for at least 9.4" width...only 1 option below would work and it's basically 60#...I would also not get a 44 psi tire - even if it's 100% fine.
Size (Nitto Recon Grappler AT)WeightDiameterMaxWidth
275/60R20 | 116S46#33"50 psi9.1"
305/55R20 | 116S51#33"44 psi10.5"
LT275/60R20 | 123/120S55#33"80 psi9.3"
LT285/60R20 | 125/122S59#33.5"80 psi9.8"
LT295/55R20 | 123/120S59#33"80 psi10.6"
275/65R20 | 116T47#34"44 psi8.8"
LT275/65R20 | 126/123S57#34"80 psi9"
315/60R20 | 116S57#35"44 psi10.5"
Ya I find the OP claim veeeeeeeery hard to believe, considering my real world over 10k miles of experience with them, and I don't think an SL 34" tire is *that* much more efficient than a XL 33" tire, if at all.
 

ksurfier

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There’s a detailed look at high efficiency 33” tires (see thread below)…tires can range from $200-$500+ each, but the real cost in the long run is charging and to battery pack (extra $500 per year with heavy tires). So an extra $1,500 per year or so…
buying a second set of tires is the way to go…
Affordable high efficiency 20" wheels and 33" tires options (275/60R20)
 

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ksurfier

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Ya I find the OP claim veeeeeeeery hard to believe, considering my real world over 10k miles of experience with them, and I don't think an SL 34" tire is *that* much more efficient than a XL 33" tire, if at all.
Definitely - But I commend them for trying something different and if it works for them that’s fantastic, would like to see a test at some point if anyone wants to give it a go…I have a good feeling for how the lightweight tires are doing efficiency wise, but 45# and above are still a bit of a mystery to me.

Anyone collecting test data needs to pay careful attention to outside temp (preferably they are 50 to 80), wind, testing on flat-ish terrain, using AP and not conserve, and getting 70-75 constant speed. Or at least 58 mph where aero losses and rolling loses are equivalent.

this is hypothetical:
Rivian R1T R1S 20" Nitto Recon Grappler AT tires 25% more efficient than Pirelli OEM AT! The holy grail! 1711139996402-u9
 

Mark_AZR1T

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I actually am a physicist but haven't done a problem like this in 13-14 years when I was in grad school. Thinking about doing the math on this problem hurts my head... :CWL:
For the record I don't have any complaints about my Recon Grapplers, other than they don't have a 3peak rating but I found they handled fine in the snow when I needed them to. In fact I have been very happy with the tread wear on the tires as well.



The LT version was the only choice for me. I flirt with the upper end of GVWR quite a bit and wanted to make sure I had that extra support.
Two physics majors in the house....;). The OP post is very informative! I tow and need the LT and am thrilled with my Cooper Discoverer AT3 XLT's, which I run at 65-70 psi and have the same efficiency as the OEM 20's.
 

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There's a very long answer that I'm not capable/interested in posting but here's a shortish version:
Below 50 psi is Standard Load tire territory, SLs typically have a lighterweight construction and aren't suitable for heavier vehicles (it's one thing to run a SL tire on a Tacoma that's 4k pounds, but the R1S fully loaded is 8.5k pounds). SL tires aren't suitable for towing either (maybe super light towing is fine). For heavy loads/towing/offroading it's important to have the tires reinforcement where it matters most (sidewall/steel belts/bead/tread/plies(1,2,3...so on)). Big part is how tire dissipates heat at speed (the second letter in 800 A'A') A = Speed > 115 MPH, B = Speed 100-115, C = 85-100. This tire has 3 things going against it for holding up and not wearing out quickly:
UTQG is 600 so it will wear faster than the OEM Pirelli (640)
Speed rating (118 mph) is lower than OEM Pirelli (130 mph)
Tread compound is softer than the OEM Pirelli (EV rated)

Clearly the tire is fine to use, it meets the load requirements, but are there better tires out there that likely meet more requirements for a heavy SUV/Truck, certainly (and they will easily get 30,000 miles instead of ~15,000):
Firestone Destination X/T - 51# 285/60R20 (33.5" Diameter and 9.9" wide)
General Grabber A/TX - 50# 275/60R20 (33.0" Diameter and 9.6" wide)
Just FYI the OEM Pirelli AT is a SL rated tire. Rivian thinks a SL rated tire is fine from the factory and they don't mention any restriction to hauling or towing with them. Not to dispute the LT tire's more rugged build but my guess is Rivian was trying to max the efficiency with the OEM tire while meeting their other payload and towing specs.
 

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The Nitto also comes in "E" rating (10 ply) versus the "SL" rating (4 ply)

Rivian R1T R1S 20" Nitto Recon Grappler AT tires 25% more efficient than Pirelli OEM AT! The holy grail! 1711153936559-8x


Also, there are "E" and "SL" of the Scorpion ATs with the E being $120 less per tire...

Cheers, Andy
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