200 Series Tire and Wheel Size Database (9 Viewers)

[AnyMal]

Thanks for replying... it made me recheck and realize I made a mistake on my original post. Down the rabbit hole I went.

The OEM tires on my LC200 are actually Metric 285/60R18, not P Metric P285/60R18. My mistake. So instead of swapping P for P, it is swapping Metric for P.

The door jamb on my LC200 specifies 33psi cold inflation on the factory 285/60R18 Dunlop Grandtrek AT23's (Load index 116, 2756lbs max load). Found this on tirepressure.org (Dunlop Grandtrek AT23 Tire Pressure Chart - https://tirepressure.org/dunlop/grandtrek-at23):

Tire Size	Load Index	Load Range	26 psi	27 psi	28 psi	29 psi	30 psi	31 psi	32 psi	33 psi	34 psi	35 psi	36 psi	37 psi	38 psi	39 psi	40 psi	41 psi	42 psi
285/60R18 116 SL	116	SL	2116 lbs	2183 lbs	2216 lbs	2304 lbs	2392 lbs	2425 lbs	2491 lbs	2579 lbs	2623 lbs	2668 lbs	2756 lbs

Here is what I found for the Yokohamas I am considering (Geolandar G015 P285/70 R17) with a 117T load index on the same site:

Tire Size Load Index Load Range 26 psi 27 psi 28 psi 29 psi 30 psi 31 psi 32 psi 33 psi 34 psi 35 psi 36 psi 37 psi 38 psi 39 psi 40 psi 41 psi 42 psi P285/70R17 117 SL 117 SL 2480 lbs 2528 lbs 2575 lbs 2623 lbs 2664 lbs 2704 lbs 2745 lbs 2789 lbs 2833 lbs 2877 lbs

So from those specs (assuming they are accurate), I am looking to match the load rating of 2579lbs at 33psi on my OEM tires with something from the Yokohama chart above. The tirepressure.org numbers are saying 28psi / 2575lbs.

Plugging those numbers into the Tire-Size calculator link you gave also recommends the same 28psi / 2575lbs.

I am still curious where you obtained the 32psi minimum in your original recommendation where you were basing your numbers on my error stating a P metric OEM? Not trying to be rude, just asking if your info comes from Yokohama, personal experience, or another verifiable source?

Hint: You are not just solving for load. There is an entire universe of other metrics and criteria your tires must meet.
Go ahead and risk your life if you like though. I am more than done on this topic.

No offense taken at all though, please dont take any offense either. Theres a long history of bull**** at work.
I should've never said anything, but i just cant let people legitimately run asinine, life threateningly low tire pressure based on a forum post.

 

[AnyMal]

what am I missing?

Nothing.

 

[wrigleyrags]

Hint: You are not just solving for load. There is an entire universe of other metrics and criteria your tires must meet.
Go ahead and risk your life if you like though. I am more than done on this topic.

No offense taken at all though, please dont take any offense either. Theres a long history of bulls*** at work.
I should've never said anything, but i just cant let people legitimately run asinine, life threateningly low tire pressure based on a forum post.

Cool.

Any other internet strangers care to share actual facts or resources explaining "the entire universe of other metrics and criteria" that non-OEM tires must meet to be safe on an LC200? The one source provided (Tire-size calculator) apparently doesn't provide factual data after all. This is concerning.

Genuinely interested in facts here. The whole point of my post was due diligence to arm myself with data before trusting the recommended psi from my local Discount Tire crew if I dare to actually make the swap...

 

[AnyMal]

Cool.

Any other internet strangers care to share actual facts or resources explaining "the entire universe of other metrics and criteria" that non-OEM tires must meet to be safe on an LC200? The one source provided (Tire-size calculator) apparently doesn't provide factual data after all. This is concerning.

Genuinely interested in facts here. The whole point of my post was due diligence to arm myself with data before trusting the recommended psi from my local Discount Tire crew if I dare to actually make the swap...

Go ahead and run 26 psi dude. Bye bye.

 

[gaijin]

Cool.

Any other internet strangers care to share actual facts or resources explaining "the entire universe of other metrics and criteria" that non-OEM tires must meet to be safe on an LC200? The one source provided (Tire-size calculator) apparently doesn't provide factual data after all. This is concerning.

Genuinely interested in facts here. The whole point of my post was due diligence to arm myself with data before trusting the recommended psi from my local Discount Tire crew if I dare to actually make the swap...

Again, I'm kind of working in the dark here, but did you not see the link I posted to the Toyo Tires doc?

Just in case you missed it, here it is again: Guidelines for the Application of Load and Inflation Tables

All the facts you need to double check Discount Tire should be in there. If you still have any questions, just post up and we'll try to fill in the gaps.

HTH

 

[wrigleyrags]

Again, I'm kind of working in the dark here, but did you not see the link I posted to the Toyo Tires doc?

Just in case you missed it, here it is again: Guidelines for the Application of Load and Inflation Tables

All the facts you need to double check Discount Tire should be in there. If you still have any questions, just post up and we'll try to fill in the gaps.

HTH

I did see that, it corroborates all of the sources I have found online and I appreciate the helpful response.

Thank you gaijin.

 

[AnyMal]

Unwatched.

 

[TeCKis300]

So from those specs (assuming they are accurate), I am looking to match the load rating of 2579lbs at 33psi on my OEM tires with something from the Yokohama chart above. The tirepressure.org numbers are saying 28psi / 2575lbs.

This is the assumption that is not exactly right. And where RCTIP is foundationally flawed.

OEM tire pressure recommendation is a balance of multiple factors including load, stability, handling, MPG, tire wear, comfort, etc. The factory 33psi was not derived solely from load. A look at the heavier sister LX570 will show that. Using load rating is useful as a first pass translation but but it needs to be cross checked and refined.

Lookup the definition about tire load and you'll see it's not even what many people assume it to be. It's about managing max temperature of the tire carcass at the max design speed and load. LTs need more pressure not because they are more delicate than Ps. But because there's more rubber and material that when the tire goes round and round, creates heat. Even as they are stiffer and will deform less.

Here's another point were RCTIP is completely failing the community and potentially putting people in danger because they assume proper diligence was done. From the "bible" reference itself. Note the highlighted and why you shouldn't use 28psi.

 

[gaijin]

This is the assumption that is not exactly right. And where RCTIP is foundationally flawed.

OEM tire pressure recommendation is a balance of multiple factors including load, stability, handling, MPG, tire wear, comfort, etc. The factory 33psi was not derived solely from load. A look at the heavier sister LX570 will show that. Using load rating is useful as a first pass translation but but it needs to be cross checked and refined.

Lookup the definition about tire load and you'll see it's not even what many people assume it to be. It's about managing max temperature of the tire carcass at the max design speed and load. LTs need more pressure not because they are more delicate than Ps. But because there's more rubber and material that when the tire goes round and round, creates heat. Even as they are stiffer and will deform less.

Here's another point were RCTIP is completely failing the community and potentially putting people in danger because they assume proper diligence was done. From the "bible" reference itself. Note the highlighted and why you shouldn't use 28psi.

View attachment 3329261

Again, I believe you are misinterpreting what is written.

Let's take a look at a more complete snippet from that same document:

The warning at the bottom refers to one's choice for the tire pressure, recommended by the manufacturer for that standard tire, as a basis for the calculations for Load.

To interpret that warning as you would, it would have to be worded:

Never use an inflation pressure [FOR THE REPLACEMENT TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

It is not worded that way, and to so interpret that way one would have to be comparing apples to oranges - so to speak.

What is a more logical interpretation is:

Never use an inflation pressure [FOR THE OEM TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

This second (and I believe correct) interpretation is borne out by the implicit assumptions for steps 4, 5 and 6 above.

HTH

 

[TeCKis300]

Again, I believe you are misinterpreting what is written.

Let's take a look at a more complete snippet from that same document:

View attachment 3329409

The warning at the bottom refers to one's choice for the tire pressure, recommended by the manufacturer for that standard tire, as a basis for the calculations for Load.

To interpret that warning as you would, it would have to be worded:

Never use an inflation pressure [FOR THE REPLACEMENT TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

It is not worded that way, and to so interpret that way one would have to be comparing apples to oranges - so to speak.

What is a more logical interpretation is:

Never use an inflation pressure [FOR THE OEM TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

This second (and I believe correct) interpretation is borne out by the implicit assumptions for steps 4, 5 and 6 above.

HTH

Are you sure?

- You're taking an interpretation of a sentence from context of a different section. The warning is clearly in the context of the section heading: Replacement Tire, i.e. interpretation 1.
- Interpretation 2 provides zero new or clarifying information. Amounts to stating something not worth saying or belongs in a prefacing section of the overall document.


More sane cross checks
- Replace a 285/60R18 with a taller profile 285/70R17. Intuitively, most would understand that's going to be softer and inherently less stable on account of a taller sidewall. But sure, let's drop the pressure 5PSI more... to make things more interesting? Gut test says 28psi can't possibly be right, because it's not.
- Almost never seen in modern OEM inflation pressures, and definitely not on a car this heavy and tall.
- Driving test feedback from testaments on this board. If it feels wrong - it's because it's wrong.

 

[shelby95]

Again, I believe you are misinterpreting what is written.

Let's take a look at a more complete snippet from that same document:

View attachment 3329409

The warning at the bottom refers to one's choice for the tire pressure, recommended by the manufacturer for that standard tire, as a basis for the calculations for Load.

To interpret that warning as you would, it would have to be worded:

Never use an inflation pressure [FOR THE REPLACEMENT TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

It is not worded that way, and to so interpret that way one would have to be comparing apples to oranges - so to speak.

What is a more logical interpretation is:

Never use an inflation pressure [FOR THE OEM TIRE] lower than what is recommended [FOR THE OEM TIRE] by the vehicle manufacturer.

This second (and I believe correct) interpretation is borne out by the implicit assumptions for steps 4, 5 and 6 above.

HTH

This seems correct to me.

Steps 5 and 6 grant that your inflation pressure for a given tire should be for a corresponding load equal to or greater than that of the OEM tire. As such, if that load is achieved at a lower inflation pressure, then so be it. You have met the criteria set forth in steps 5 and 6.

 

[shelby95]

To further the argument to an extreme, if the tire were solid rubber do you still feel that inflation pressure should be the same or greater than OEM?

 

[gaijin]

Are you sure?

Yes.

 

[Gorilla]

Mounted some TE37XT on mine this week, has some Michelin LTX All Terrains in 285/60/18. Seeing I hardly take this off road anymore, Its nice to have the confort of these tyres but just by the looks I think ill go back to some Nitto Grapplers in 285/65/18

 

[TeCKis300]

Litmus test.

LX570 with OEM P285/50R20 and I want to replace it with a P285/65R18 tire. What is the inflation pressure of the replacement tire?

By RCTIP methodology, a P285/50R20 SL Load Capacity: 2315 lbs @ 33 psi maps to a P285/60R18 SL Load Capacity: 2348 lbs @ 29 psi.

Except that is wrong because we know for a 200-series in LC200 flavor fitted with factory 285/60R28 asks for 33 PSI.

The Tire Load Reference tells us this using the proper interpretation, that the replacement tire should not use a lower pressure.

Another example, LX570 with OEM P275/50R21 replacing with P285/50R20. RCTIP says P275/50R21 XL Load Capacity: 2087 lbs @ 33 psi maps to a P285/50R20 SL Load Capacity: 2098 lbs @ 27 psi.

Again, our cheat sheet - aka factory recommendations for OEM installed sizes says the right answer is P285/50R20 @ 33 PSI

Let's reinforce what the The Tire Load Reference actually tells us again, that the replacement tire should not use a lower pressure.

 

[gaijin]

Litmus test.

LX570 with OEM P285/50R20 and I want to replace it with a P285/65R18 tire. What is the inflation pressure of the replacement tire?

By RCTIP methodology, a P285/50R20 SL Load Capacity: 2315 lbs @ 33 psi maps to a P285/60R18 SL Load Capacity: 2348 lbs @ 29 psi.

Except that is wrong because we know for a 200-series in LC200 flavor fitted with factory 285/60R28 asks for 33 PSI.

The Tire Load Reference tells us this using the proper interpretation, that the replacement tire should not use a lower pressure.

View attachment 3330287

Another example, LX570 with OEM P275/50R21 replacing with P285/50R20. RCTIP says P275/50R21 XL Load Capacity: 2087 lbs @ 33 psi maps to a P285/50R20 SL Load Capacity: 2098 lbs @ 27 psi.

Again, our cheat sheet - aka factory recommendations for OEM installed sizes says the right answer is P285/50R20 @ 33 PSI

Let's reinforce what the The Tire Load Reference actually tells us again, that the replacement tire should not use a lower pressure.

View attachment 3330287




Figures. Consider the damage you've done to the community because you're too proud of your RCTIP narrative to continue to learn.

I'll ignore your ad hominem attack and stick to the facts. Is that OK with you?

Your first example is mixing apples and oranges. The URJ200 platform (LC200) and the URJ201 platform (LX570) obviously have different engineering considerations by the manufacturer(s). As I have stated many times:

Toyota/Lexus engineered the suspensions on the two vehicles to provide optimum safe performance with different tire spring rates (i.e. tire pressures). Different vehicles, different suspensions, different engineering considerations from the manufacturer - simple as that.

This requires different RCTIP calculations for each platform. And, as you well know, the URJ201 platform was never available from Lexus with P285/60R18 tires. To assume that a RCTIP for the URJ200 platform is appropriate for the URJ201 platform is simply false.

Your second example is more interesting.

I have never recommended a tire pressure for the LX570 based on the ISO-Metric 275/50R21 XL 113V tire (the P-Metric P275/50R21 tire you reference in your post was never offered by Lexus), I base all my LX570 recommendations on the P285/50R20 tire which was commonly available across all years of manufacture. I do this for exactly the case you mention.

So... I still stand by my interpretation of the warning.

HTH

 

[ThRiLlGmYr]

Wow, tire inflation is serious business. I always thought of it as a tire wear and fuel economy issue, but I am just a few PSI away from certain death.

 

[lx200inAR]

I'll ignore your ad hominem attack and stick to the facts. Is that OK with you?

Your first example is mixing apples and oranges. The URJ200 platform (LC200) and the URJ201 platform (LX570) obviously have different engineering considerations by the manufacturer(s). As I have stated many times:

Toyota/Lexus engineered the suspensions on the two vehicles to provide optimum safe performance with different tire spring rates (i.e. tire pressures). Different vehicles, different suspensions, different engineering considerations from the manufacturer - simple as that.

This requires different RCTIP calculations for each platform. And, as you well know, the URJ201 platform was never available from Lexus with P285/60R18 tires. To assume that a RCTIP for the URJ200 platform is appropriate for the URJ201 platform is simply false.

Your second example is more interesting.

I have never recommended a tire pressure for the LX570 based on the ISO-Metric 275/50R21 XL 113V tire (the P-Metric P275/50R21 tire you reference in your post was never offered by Lexus), I base all my LX570 recommendations on the P285/50R20 tire which was commonly available across all years of manufacture. I do this for exactly the case you mention.

So... I still stand by my interpretation of the warning.

HTH

just so I’m following along,

Example 1: not okay to impart some common sense and must abide by “the rules.”

Example 2: it’s okay to impart some common sense…rules be damned.

Got It!

 

[TeCKis300]

To understand why it's 33 psi, and why that carries broadly through most P tires.

Fundamentally, it's useful to understand how tires work. It might not be intuitive but it's not the tire carcass that supports the car, it is the air. Reference here and here, or do your own research. The tire is more a containment vessel for air to support the car (among other things).

It will take a second for that to sink in. But assuming that understanding, it easier to see why when changing tire sizes, the support need stays the same, so it should be at a minimum the same pressure recommended by factory.

The exception here is that as we often talk about LT tires, where air is needed to do more than support the car. The increased air pressure is to protect the heavier LT tires from heat generated as it goes round and round flexing. P tires with less mass and material generate less heat for the same load and is why they can use less pressure.

To further the argument to an extreme, if the tire were solid rubber do you still feel that inflation pressure should be the same or greater than OEM?

Greater. As explained above, it is solely to prevent heat build-up for more material and rubber. It's not driven by the need to support load as is the common mis-understanding for increased pressures on LT tires.

The more useful question is what if you take the air out of a tire. Doesn't matter P, LT, Load Range anything.

It goes flat.

That's a fact and helps understand that it is air that fundamentally supports the car. And why RCTIP as defined is ridiculous and would be obvious to anyone that's tried pressure in the lower ranges.

Any why again - the replacement tire should never use a lower pressure than OEM for the replacement tire for normal use. Even if inflation tables suggest is possible from a heat management perspective.

 

[shelby95]

To understand why it's 33 psi, and why that carries broadly through most P tires.

Fundamentally, it's useful to understand how tires work. It might not be intuitive but it's not the tire carcass that supports the car, it is the air. Reference here and here, or do your own research. The tire is more a containment vessel for air to support the car (among other things).

It will take a second for that to sink in. But assuming that understanding, it easier to see why when changing tire sizes, the support need stays the same, so it should be at a minimum the same pressure recommended by factory.

The exception here is that as we often talk about LT tires, where air is needed to do more than support the car. The increased air pressure is to protect the heavier LT tires from heat generated as it goes round and round flexing. P tires with less mass and material generate less heat for the same load and is why they can use less pressure.



Greater. As explained above, it is solely to prevent heat build-up for more material and rubber. It's not driven by the need to support load as is the common mis-understanding for increased pressures on LT tires.

The more useful question is what if you take the air out of a tire. Doesn't matter P, LT, Load Range anything.

It goes flat.

That's a fact and helps understand that it is air that fundamentally supports the car. And why RCTIP as defined is ridiculous and would be obvious to anyone that's tried pressure in the lower ranges.

Any why again - the replacement tire should never use a lower pressure than OEM for the replacement tire for normal use. Even if inflation tables suggest is possible from a heat management perspective.

“Greater. As explained above, it is solely to prevent heat build-up for more material and rubber. It's not driven by the need to support load as is the common mis-understanding for increased pressures on LT tires.”

A greater pressure prevents heat build up?
The “more material and rubber” creates more heat buildup? It’s not the load?

You may want to brush up on gas laws and material and thermodynamics.