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
Tire Pressure recommendation (6 Viewers)
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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.
| Size | Sidewall (in) | LC | LX |
| LT255/75R17 | 7.53 | 47 PSI | 42 PSI |
| P255/75R17 | 7.53 | 35 PSI | 29 PSI |
| LT275/70R17 | 7.58 | 43 PSI | 38 PSI |
| LT345/55R17 | 7.47 | 36 PSI | 35 PSI |
| LT285/70R17 | 7.85 | 40 PSI | 35 PSI |
| P285/70R17 | 7.85 | 27 PSI | 26 PSI |
| LT305/65R17 | 7.81 | 38 PSI | 35 PSI |
| 33x10.50R17LT | 8 | 46 PSI | 40 PSI |
| LT255/80R17 | 8.03 | 44 PSI | 40 PSI |
| P255/80R17 | 8.03 | 33 PSI | 29 PSI |
| 33x12.50R17LT | 8 | 41 PSI | 37 PSI |
| LT295/70R17 | 8.13 | 37 PSI | 35 PSI |
| 34x10.50R17LT | 8.5 | 41 PSI | 36 PSI |
| LT285/75R17 | 8.42 | 37 PSI | 35 PSI |
| LT305/70R17 | 8.41 | 35 PSI | 35 PSI |
| LT275/80R17 | 8.66 | 38 PSI | 35 PSI |
| LT295/75R17 | 8.71 | 35 PSI | 35 PSI |
| LT315/70R17 | 8.68 | 35 PSI | 35 PSI |
| 35x10.50R17LT | 9 | 37 PSI | 33 PSI |
| 35x11.50R17LT | 9 | 34 PSI | 31 PSI |
| 35x12.50R17LT | 9 | 33 PSI | 30 PSI |
| LT325/70R17 | 8.96 | 35 PSI | 35 PSI |
| 36x14.50R17LT | 9.5 | 28 PSI | 25 PSI |
| LT355/70R17 | 9.78 | 35 PSI | 35 PSI |
| 37x12.50R17LT | 10 | 28 PSI | 25 PSI |
| 37x12.50R17LT | 10 | 28 PSI | 25 PSI |
| 37x13.50R17LT | 10 | 27 PSI | 25 PSI |
| 38x13.50R17LT | 10.5 | 25 PSI | 25 PSI |
| 38x14.50R17LT | 10.5 | 25 PSI | 25 PSI |
| 38x15.50R17LT | 10.5 | 25 PSI | 25 PSI |
| 39x13.50R17LT | 11 | 25 PSI | 25 PSI |
| 40x13.50R17LT | 11.5 | 25 PSI | 25 PSI |
| 40x14.50R17LT | 11.5 | 25 PSI | 25 PSI |
| LT255/70R18 | 7.03 | 47 PSI | 42 PSI |
| P255/70R18 | 7.03 | NA | 31 PSI |
| LT275/65R18 | 7.04 | 45 PSI | 40 PSI |
| P275/65R18 | 7.04 | 33 PSI | 28 PSI |
| LT265/70R18 | 7.3 | 44 PSI | 39 PSI |
| P265/70R18 | 7.3 | 32 PSI | 27 PSI |
| LT285/65R18 | 7.29 | 42 PSI | 37 PSI |
| LT305/60R18 | 7.2 | 40 PSI | 35 PSI |
| 33x10.50R18LT | 7.5 | 49 PSI | 43 PSI |
| 33x11.50R18LT | 7.5 | 46 PSI | 41 PSI |
| LT275/70R18 | 7.58 | 41 PSI | 36 PSI |
| P275/70R18 | 7.58 | 32 PSI | 28 PSI |
| LT295/65R18 | 7.55 | 39 PSI | 35 PSI |
| 33x12.50R18LT | 7.5 | 44 PSI | 39 PSI |
| LT375/50R18 | 7.38 | 35 PSI | 35 PSI |
| LT285/70R18 | 7.85 | 38 PSI | 35 PSI |
| LT305/65R18 | 7.81 | 35 PSI | 35 PSI |
| LT325/60R18 | 7.68 | 35 PSI | 35 PSI |
| 34x12.50R18LT | 8 | 39 PSI | 35 PSI |
| LT295/70R18 | 8.13 | 35 PSI | 35 PSI |
| LT325/65R18 | 8.32 | 35 PSI | 35 PSI |
| LT345/60R18 | 8.15 | 35 PSI | 35 PSI |
| LT285/75R18 | 8.42 | 35 PSI | 35 PSI |
| 35x11.50R18LT | 8.5 | 37 PSI | 33 PSI |
| LT305/70R18 | 8.41 | 35 PSI | 35 PSI |
| 35x12.50R18LT | 8.5 | 35 PSI | 31 PSI |
| 35x13.50R18LT | 8.5 | 33 PSI | 30 PSI |
| LT275/80R18 | 8.66 | 35 PSI | 35 PSI |
| LT315/70R18 | 8.68 | 35 PSI | 35 PSI |
| LT375/60R18 | 8.86 | 35 PSI | 35 PSI |
| LT305/75R18 | 9.01 | 35 PSI | 35 PSI |
| 36x13.50R18LT | 9 | 30 PSI | 27 PSI |
| 36x14.50R18LT | 9 | 29 PSI | 26 PSI |
| LT355/65R18 | 9.08 | 35 PSI | 35 PSI |
| 37x11.50R18LT | 9.5 | 30 PSI | 27 PSI |
| 37x12.50R18LT | 9.5 | 29 PSI | 26 PSI |
| 37x13.50R18LT | 9.5 | 28 PSI | 25 PSI |
| 38x14.50R18LT | 10 | 25 PSI | 25 PSI |
| 38x15.50R18LT | 10 | 25 PSI | 25 PSI |
| LT395/65R18 | 10.11 | 35 PSI | 35 PSI |
| 40x14.50R18LT | 11 | 25 PSI | 25 PSI |
| LT275/55R20 | 5.95 | 51 PSI | 46 PSI |
| P275/55R20 | 5.95 | NA | 32 PSI |
| LT305/50R20 | 6 | 50 PSI | 44 PSI |
| LT265/60R20 | 6.26 | 49 PSI | 43 PSI |
| P265/60R20 | 6.26 | NA | 33 PSI |
| LT285/55R20 | 6.17 | 48 PSI | 43 PSI |
| P285/55R20 | 6.17 | 35 PSI | 31 PSI |
| LT315/50R20 | 6.2 | 45 PSI | 40 PSI |
| LT275/60R20 | 6.5 | 45 PSI | 40 PSI |
| P275/60R20 | 6.5 | 33 PSI | 28 PSI |
| 33x11.50R20LT | 6.5 | 55 PSI | 49 PSI |
| LT295/55R20 | 6.39 | 45 PSI | 40 PSI |
| 33x12.50R20LT | 6.5 | 53 PSI | 47 PSI |
| LT305/55R20 | 6.6 | 42 PSI | 36 PSI |
| P305/55R20 | 6.6 | 32 PSI | 28 PSI |
| LT325/50R20 | 6.4 | 43 PSI | 38 PSI |
| 33x13.50R20LT | 6.5 | 51 PSI | 45 PSI |
| LT285/60R20 | 6.73 | 42 PSI | 38 PSI |
| 34x11.50R20LT | 7 | 47 PSI | 42 PSI |
| LT275/65R20 | 7.04 | 41 PSI | 36 PSI |
| LT295/60R20 | 6.97 | 39 PSI | 35 PSI |
| LT285/65R20 | 7.29 | 38 PSI | 35 PSI |
| LT305/60R20 | 7.2 | 36 PSI | 35 PSI |
| LT335/55R20 | 7.25 | 35 PSI | 35 PSI |
| 35x11.50R20LT | 7.5 | 42 PSI | 37 PSI |
| LT295/65R20 | 7.55 | 35 PSI | 35 PSI |
| 35x12.50R20LT | 7.5 | 40 PSI | 36 PSI |
| LT315/60R20 | 7.44 | 35 PSI | 35 PSI |
| P315/60R20 | 7.44 | 32 PSI | 28 PSI |
| 35x13.50R20LT | 7.5 | 39 PSI | 34 PSI |
| LT325/60R20 | 7.68 | 35 PSI | 35 PSI |
| 36x15.50R20LT | 8 | 32 PSI | 29 PSI |
| 37x11.50R20LT | 8.5 | 33 PSI | 30 PSI |
| 37x12.50R20LT | 8.5 | 32 PSI | 28 PSI |
| 37x13.50R20LT | 8.5 | 30 PSI | 27 PSI |
| LT355/60R20 | 8.39 | 35 PSI | 35 PSI |
| 37x14.50R20LT | 8.5 | 29 PSI | 27 PSI |
| LT315/70R20 | 8.68 | 35 PSI | 35 PSI |
| 38x13.50R20LT | 9 | 28 PSI | 25 PSI |
| 38x14.50R20LT | 9 | 27 PSI | 25 PSI |
| 38x15.50R20LT | 9 | 26 PSI | 25 PSI |
| LT325/75R20 | 9.6 | 35 PSI | 35 PSI |
| 40x13.50R20LT | 10 | 25 PSI | 25 PSI |
| 40x14.50R20LT | 10 | 25 PSI | 25 PSI |
| 40x15.50R20LT | 10 | 25 PSI | 25 PSI |
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:
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.
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.
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.
| LT275/60R20 | 6.5 | 45 PSI | 40 PSI |
| P275/60R20 | 6.5 | 33 PSI | 28 PSI |
| 33x11.50R20LT | 6.5 | 55 PSI | 49 PSI |
Agreed. Responsible RCTIP recommendation should really come with some further guidance and cautions.
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?
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.
More than you want to know
This is the document i used to create the table above. Just added in the "calculations" for applying it to the LC and LX.
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?
What is the RCTIP for BFG KO2 285/70/17 C load rated, on Rock warrior wheels and 2018 LC200 stock?
Post in thread 'Tire Pressure recommendation'
Tire Pressure recommendation - https://forum.ih8mud.com/threads/tire-pressure-recommendation.997546/post-14512775
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.
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.
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.
