Tire Pressure recommendation (1 Viewer)

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Add to that confusion that the closest Floatation tires size to yours (33x11.5R20) “requires” 10 more PSI than the LT rated 275/60R20 and things get weird fast.
Wow so a flotation 33” tire needs like 50 psi?

I didn’t know that and wouldn’t have guessed that. Lt 33” is around 40 psi and Passenger 33” is 27 psi.

Tires construction and safety margins are odd
 
Wow so a flotation 33” tire needs like 50 psi?

I didn’t know that and wouldn’t have guessed that. Lt 33” is around 40 psi and Passenger 33” is 27 psi.

Tires construction and safety margins are odd
Indeed,

Here's a link to the tables i posted that show all the tire sizes in the RCTIP tables applied ot the OEM RCTIP for LX and LCs.

Maybe i should resort them by tire size regardless of tire construction.
 
The forum has a character limit that i'm not getting anywhere near. The table format must add a lot under the hood. I've removed a lot of info in order to get it all in one post.

SizeSidewall (in)LCLX
LT255/75R17
7.53​
47 PSI42 PSI
P255/75R17
7.53​
35 PSI29 PSI
LT275/70R17
7.58​
43 PSI38 PSI
LT345/55R17
7.47​
36 PSI35 PSI
LT285/70R17
7.85​
40 PSI35 PSI
P285/70R17
7.85​
27 PSI26 PSI
LT305/65R17
7.81​
38 PSI35 PSI
33x10.50R17LT
8​
46 PSI40 PSI
LT255/80R17
8.03​
44 PSI40 PSI
P255/80R17
8.03​
33 PSI29 PSI
33x12.50R17LT
8​
41 PSI37 PSI
LT295/70R17
8.13​
37 PSI35 PSI
34x10.50R17LT
8.5​
41 PSI36 PSI
LT285/75R17
8.42​
37 PSI35 PSI
LT305/70R17
8.41​
35 PSI35 PSI
LT275/80R17
8.66​
38 PSI35 PSI
LT295/75R17
8.71​
35 PSI35 PSI
LT315/70R17
8.68​
35 PSI35 PSI
35x10.50R17LT
9​
37 PSI33 PSI
35x11.50R17LT
9​
34 PSI31 PSI
35x12.50R17LT
9​
33 PSI30 PSI
LT325/70R17
8.96​
35 PSI35 PSI
36x14.50R17LT
9.5​
28 PSI25 PSI
LT355/70R17
9.78​
35 PSI35 PSI
37x12.50R17LT
10​
28 PSI25 PSI
37x12.50R17LT
10​
28 PSI25 PSI
37x13.50R17LT
10​
27 PSI25 PSI
38x13.50R17LT
10.5​
25 PSI25 PSI
38x14.50R17LT
10.5​
25 PSI25 PSI
38x15.50R17LT
10.5​
25 PSI25 PSI
39x13.50R17LT
11​
25 PSI25 PSI
40x13.50R17LT
11.5​
25 PSI25 PSI
40x14.50R17LT
11.5​
25 PSI25 PSI
LT255/70R18
7.03​
47 PSI42 PSI
P255/70R18
7.03​
NA31 PSI
LT275/65R18
7.04​
45 PSI40 PSI
P275/65R18
7.04​
33 PSI28 PSI
LT265/70R18
7.3​
44 PSI39 PSI
P265/70R18
7.3​
32 PSI27 PSI
LT285/65R18
7.29​
42 PSI37 PSI
LT305/60R18
7.2​
40 PSI35 PSI
33x10.50R18LT
7.5​
49 PSI43 PSI
33x11.50R18LT
7.5​
46 PSI41 PSI
LT275/70R18
7.58​
41 PSI36 PSI
P275/70R18
7.58​
32 PSI28 PSI
LT295/65R18
7.55​
39 PSI35 PSI
33x12.50R18LT
7.5​
44 PSI39 PSI
LT375/50R18
7.38​
35 PSI35 PSI
LT285/70R18
7.85​
38 PSI35 PSI
LT305/65R18
7.81​
35 PSI35 PSI
LT325/60R18
7.68​
35 PSI35 PSI
34x12.50R18LT
8​
39 PSI35 PSI
LT295/70R18
8.13​
35 PSI35 PSI
LT325/65R18
8.32​
35 PSI35 PSI
LT345/60R18
8.15​
35 PSI35 PSI
LT285/75R18
8.42​
35 PSI35 PSI
35x11.50R18LT
8.5​
37 PSI33 PSI
LT305/70R18
8.41​
35 PSI35 PSI
35x12.50R18LT
8.5​
35 PSI31 PSI
35x13.50R18LT
8.5​
33 PSI30 PSI
LT275/80R18
8.66​
35 PSI35 PSI
LT315/70R18
8.68​
35 PSI35 PSI
LT375/60R18
8.86​
35 PSI35 PSI
LT305/75R18
9.01​
35 PSI35 PSI
36x13.50R18LT
9​
30 PSI27 PSI
36x14.50R18LT
9​
29 PSI26 PSI
LT355/65R18
9.08​
35 PSI35 PSI
37x11.50R18LT
9.5​
30 PSI27 PSI
37x12.50R18LT
9.5​
29 PSI26 PSI
37x13.50R18LT
9.5​
28 PSI25 PSI
38x14.50R18LT
10​
25 PSI25 PSI
38x15.50R18LT
10​
25 PSI25 PSI
LT395/65R18
10.11​
35 PSI35 PSI
40x14.50R18LT
11​
25 PSI25 PSI
LT275/55R20
5.95​
51 PSI46 PSI
P275/55R20
5.95​
NA32 PSI
LT305/50R20
6​
50 PSI44 PSI
LT265/60R20
6.26​
49 PSI43 PSI
P265/60R20
6.26​
NA33 PSI
LT285/55R20
6.17​
48 PSI43 PSI
P285/55R20
6.17​
35 PSI31 PSI
LT315/50R20
6.2​
45 PSI40 PSI
LT275/60R20
6.5​
45 PSI40 PSI
P275/60R20
6.5​
33 PSI28 PSI
33x11.50R20LT
6.5​
55 PSI49 PSI
LT295/55R20
6.39​
45 PSI40 PSI
33x12.50R20LT
6.5​
53 PSI47 PSI
LT305/55R20
6.6​
42 PSI36 PSI
P305/55R20
6.6​
32 PSI28 PSI
LT325/50R20
6.4​
43 PSI38 PSI
33x13.50R20LT
6.5​
51 PSI45 PSI
LT285/60R20
6.73​
42 PSI38 PSI
34x11.50R20LT
7​
47 PSI42 PSI
LT275/65R20
7.04​
41 PSI36 PSI
LT295/60R20
6.97​
39 PSI35 PSI
LT285/65R20
7.29​
38 PSI35 PSI
LT305/60R20
7.2​
36 PSI35 PSI
LT335/55R20
7.25​
35 PSI35 PSI
35x11.50R20LT
7.5​
42 PSI37 PSI
LT295/65R20
7.55​
35 PSI35 PSI
35x12.50R20LT
7.5​
40 PSI36 PSI
LT315/60R20
7.44​
35 PSI35 PSI
P315/60R20
7.44​
32 PSI28 PSI
35x13.50R20LT
7.5​
39 PSI34 PSI
LT325/60R20
7.68​
35 PSI35 PSI
36x15.50R20LT
8​
32 PSI29 PSI
37x11.50R20LT
8.5​
33 PSI30 PSI
37x12.50R20LT
8.5​
32 PSI28 PSI
37x13.50R20LT
8.5​
30 PSI27 PSI
LT355/60R20
8.39​
35 PSI35 PSI
37x14.50R20LT
8.5​
29 PSI27 PSI
LT315/70R20
8.68​
35 PSI35 PSI
38x13.50R20LT
9​
28 PSI25 PSI
38x14.50R20LT
9​
27 PSI25 PSI
38x15.50R20LT
9​
26 PSI25 PSI
LT325/75R20
9.6​
35 PSI35 PSI
40x13.50R20LT
10​
25 PSI25 PSI
40x14.50R20LT
10​
25 PSI25 PSI
40x15.50R20LT
10​
25 PSI25 PSI
 
I’ve been going down this rabbit hole. RCTIP seems best utilized as a minimum safe pressure with an increase being necessary until the vehicle is stable and handles appropriately and you don’t exceed the maximum.

This is why I’m not too satisfied with my lt275 60 r20 k02’s…their minimum psi to meet the load handling characteristics of the oem passenger rated tire require 40-43 psi…which is jarring.

In limited testing I found that 29 psi in the k02’s felt perfect comfort wise. However this is less than the 35 psi minimum that you’re technically supposed to run an lt tire…and even at 35 with that particular tire, the load it’s graded to carry isn’t high enough to be safe for our vehicle.

Handling wise I’m not sure 29 is good yet…but all this RCTIP stuff motivated me to purchase some non light truck cooper at3 discoverer at3 4s’s in 275 60 r20 which should allow me to safely run the 29ish psi that felt good…or 33 like oem should that handle well.

Hopefully 29 psi in the non lt tires feels as squishy as 29 psi in the lt k02’s did but only time will tell.

It is ironic that a passenger rated tire is supposedly capable of a higher/safer load carrying capacity than a light truck k02 at the same 29 psi…but so it goes apparently. One wouldn’t expect that a tough lt tire would be weaker and more dangerous than a passenger rated tire.

There's further evil in RCTIP at least when interpreted for the LC. It is not the minimum many assume. That is because the factory inflation pressure was never solely based on load carrying. It was likely tailored up for stability and handling.

We know this because the LX is heavier (but same GVWR). It has the same general guidance for factory inflation pressure. The LX RCTIP represents a closer minimum that can be used across the board for all 200-series.

There's actually a danger in using tires that need too high of inflation pressure. Both anecdotally and via the Load Inflation Table reference. People have reported that certain tires needing 40+PSI, when run with the factory suspension, will literally skip across the road at speed because the sidewall spring rates are too high for proper control and handling. Not sure how the RCTIP gospel can still be pushed given that. The very reference itself even cautions this:
1657207910782.png
 
Add to that confusion that the closest Floatation tires size to yours (33x11.5R20) “requires” 10 more PSI than the LT rated 275/60R20 and things get weird fast.

Not all floatation sizes need those pressures. My 35x12.5R20s via RCTIP recommends 35PSI. But it's a marshmallow at that pressure. For handling and safety, I find it better to run 38 PSI.

And then you have the other end of the spectrum where someone with a 37x12.5R17...incredibly tall sidewalls are told to run 25 PSI. :meh:
 
Not all floatation sizes need those pressures. My 35x12.5R20s via RCTIP recommends 35PSI. But it's a marshmallow at that pressure. For handling and safety, I find it better to run 38 PSI.

And then you have the other end of the spectrum where someone with a 37x12.5R17...incredibly tall sidewalls are told to run 25 PSI. :meh:

Yeah, i was definitely speaking very specifically about that tire size. I just noticed it was somewhat anomalous with the wide range of recommended PSI for nearly the same size tire from 28-49 PSI depending on P-Metric, LT-Metric, and Floatation. I can't imagine an LX feels even remotely safe at 28 PSI on a 33" tire.

LT275/60R206.545 PSI40 PSI
P275/60R206.533 PSI28 PSI
33x11.50R20LT6.555 PSI49 PSI
 
Yeah, i was definitely speaking very specifically about that tire size. I just noticed it was somewhat anomalous with the wide range of recommended PSI for nearly the same size tire from 28-49 PSI depending on P-Metric, LT-Metric, and Floatation. I can't imagine an LX feels even remotely safe at 28 PSI on a 33" tire.

LT275/60R206.545 PSI40 PSI
P275/60R206.533 PSI28 PSI
33x11.50R20LT6.555 PSI49 PSI

Agreed. Responsible RCTIP recommendation should really come with some further guidance and cautions.
 
There's further evil in RCTIP at least when interpreted for the LC. It is not the minimum many assume. That is because the factory inflation pressure was never solely based on load carrying. It was likely tailored up for stability and handling.

We know this because the LX is heavier (but same GVWR). It has the same general guidance for factory inflation pressure. The LX RCTIP represents a closer minimum that can be used across the board for all 200-series.

There's actually a danger in using tires that need too high of inflation pressure. Both anecdotally and via the Load Inflation Table reference. People have reported that certain tires needing 40+PSI, when run with the factory suspension, will literally skip across the road at speed because the sidewall spring rates are too high for proper control and handling. Not sure how the RCTIP gospel can still be pushed given that. The very reference itself even cautions this:
View attachment 3052629
Great point: go too far outside oem squishyness and even if your load handling is fine, you edge into other dangerous places.

The question that then arises for me is:
If one puts a 34 or 35 inch tire on the vehicle, at what pressure should one then run to not only meet minimum load requirements, but also meet minimum “handling” requirements…how would one estimate or measure for such a thing?
 
Yeah, i was definitely speaking very specifically about that tire size. I just noticed it was somewhat anomalous with the wide range of recommended PSI for nearly the same size tire from 28-49 PSI depending on P-Metric, LT-Metric, and Floatation. I can't imagine an LX feels even remotely safe at 28 PSI on a 33" tire.

LT275/60R206.545 PSI40 PSI
P275/60R206.533 PSI28 PSI
33x11.50R20LT6.555 PSI49 PSI
Felt quite comfortable at 29…whether it handles well I haven’t really tried. The nice thing about a passenger 33” tire is that I can safely run it at 29-40 psi…whereas with the lt tire I have to start at 40…and 40 feels fine 97% of the time. It’s just the 3% of the time where the road is a bit rough that the bumps exceed the dampening of the ahc and feel jarring.
 
@gaijin, looking for your knowledge and assistance! 2010 LX570 with 37x12.50R17 LT 124Q D2 RBL? I tried using the tables and came up with somewhere between 25-30psi, but was hoping for your insight. Thanks in advance!
I ran 25-26psi comfortably in that tire size over the last year, including some very spirited driving over mountain passes. I’m no RCTIP genius, just my feedback. As always, feel out any new changes and slowly get comfortable with the handling characteristics 🤙🏼
 
Tried finding it In the thread but was unsuccessful….

What is the RCTIP for BFG KO2 285/70/17 C load rated, on Rock warrior wheels and 2018 LC200 stock?
 
Am I missing something? I do not see 285/70/17 C rated.

In this case rhe rating does’t matter. To be clear, yours is the LT version and not the P-Metric. And since heading is not in that snip. It’s 40PSI for the Land Cruiser.

AA570FA1-5063-4D9C-9C38-4D96C70DB65A.jpeg
 
Perfect, That helps. Thank you!
Anyone have experience w how a 285 70 r17 feels at 40 psi vs a 20” oem tire at 33 psi?

Wondering whether 40 psi in a tire with a much larger volume of squish and sidewall feels softer or harder than a 20” oem tire with less volume of air but also less pressure.
 
In this case rhe rating does’t matter. To be clear, yours is the LT version and not the P-Metric. And since heading is not in that snip. It’s 40PSI for the Land Cruiser.

View attachment 3054298
Quite interesting that the P version of that size is only 27 psi. Seems low but I trust the numbers.
 
Quite interesting that the P version of that size is only 27 psi. Seems low but I trust the numbers.
The nice thing about the p version is that you can run a higher pressure than the 27 if you want. That’s just the minimum…the p version allows you to tune your pressure not just for minimum load, but for handling as well.
 

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