Tire Pressure recommendation (6 Viewers)

[gaijin]

^This guy gets it. Absolutely spot on.

LC owners should really consider the opportunity for a better ride.

^This guy will never get it. He knows LC200 and LX570 have different tire pressure requirements, but because he owns an LX570 he thinks everyone should run LX570 pressures.

Please feel free to ignore his advice to LC200 owners.

 

[gaijin]

@gaijin Can you tell me the recommended pressure for the Toyo AT3 LT285/75R17 117/114Q C on Rock Warriors on a Lexus LX570?
I appreciate it.
Thanks

Glad to!

The RCTIP (Recommended Cold Tire Inflation Pressure for those LT285/75R17 tires on your LX570 is 35psi F/R.

HTH

 

[gaijin]

What is the recommended tire pressure for a 2015 LC with 400-500 lbs of additional weight on 285-75-17 E load Falken Wildpeak AT3W’s.
thank you!

The RCTIP for those LT285/75R17/E Falken Wildpeak A/T3W tires on your LC200 is 37psi F/R. This pressure is good for all weight up to the GVWR of the vehicle.

HTH

 

[gaijin]

Wow impressive thread @gaijin ill ask mine too

285/70/27 maxxis razr on an Aussie 200 weighing in around 3.3T

Sorry, but I need more info about your "Aussie 200" to give you a good answer. Can you post a pic of the TIP (Tire Information Placard) found on the driver side door jamb of your vehicle? After I see that, I can answer your question.

While your at it, please confirm whether your tires are LT285/70R17 121/118Q Load Range E Razr MT tires.

Thanks.

 

[gaijin]

Me too. Going to pull the trigger soon and should be prepared.

2017 LX with 18" Tundra wheels.
And Toyo Open Country AT3

• LT275/70R18 125/122S E
• UTQG: None
• Style: Blackwall

Thank you very much in advance. I assume it is somewhere around 41 psi?

Excellent question.

The RCTIP for those LT275/70R18 tires on your LX570 is 36psi F/R.

HTH

 

[iqbal624]

The RCTIP for those LT285/75R17/E Falken Wildpeak A/T3W tires on your LC200 is 37psi F/R. This pressure is good for all weight up to the GVWR of the vehicle.

HTH

Thank you for that!

and for airing down, you'd go to 50% of that to start? Does that change based on the conditions? I have typically aired down to 20-25psi for PNW dirt/root/light mud trails but looking to plan for Moab, should i be higher? lower?

 

[TeCKis300]

^This guy will never get it. He knows LC200 and LX570 have different tire pressure requirements, but because he owns an LX570 he thinks everyone should run LX570 pressures.

Please feel free to ignore his advice to LC200 owners.

You can continue your narrative and plenty will follow. Just know that the advice you share, especially one shared as broadly as yours, impacts others.

It's obvious you believe in your advice and it may seem safe and sound. And it is. I myself have benefitted in learning and thank you for that.

But the reality is people invest time and money to do what they think is presented here as definitive. Only to then realize it's not for them. We've seen threads of this, where people put in their money, time, and frustration. Only to realize the ride quality based on LC RTCTIP is not good. Would you rather them go full circle and return to stock? Or give them opportunities to further tune their ride quality in a safe manner?

There's been learning since that every 200-series owners should take advantage of. The LX, no matter how you want to couch it, is absolutely a 200-series deep and through. LX570 RCTIP can be used for the LC. It is heavier after all. Suspension does not change that.

LX570 derived RCTIP pressures are a great and safe opportunity for every 200-series variant including LCs.

 

[iqbal624]

You can continue your narrative and plenty will follow. Just know that the advice you share, especially one shared as broadly as yours, impacts others.

It's obvious you believe in your advice and it may seem safe and sound. And it is. I myself have benefitted in learning and thank you for that.

But the reality is people invest time and money to do what they think is presented here as definitive. Only to then realize it's not for them. We've seen threads of this, where people put in their money, time, and frustration. Only to realize the ride quality based on LC RTCTIP is not good. Would you rather them go full circle and return to stock? Or give them opportunities to further tune their ride quality in a safe manner?

There's been learning since that every 200-series owners should take advantage of. The LX, no matter how you want to couch it, is absolutely a 200-series deep and through. LX570 RCTIP can be used for the LC. It is heavier after all. Suspension does not change that.

LX570 derived RCTIP pressures are a great and safe opportunity for every 200-series variant including LCs.

Pardon my ignorance, typically, how much do the pressures vary from LC200 to LX570. What are the trade-offs? I'm guessing the LX uses lower pressures to allow for a more comfortable ride. Is that accurate?

How much would a couple PSI really impact safety? I know that before people get these PSI's they have been running pressures all over the place. I know in previous vehicles I always have overinflated a bit to account for my driving habits.

Thoughts @gaijin

 

[Chewbacca]

Me too. Going to pull the trigger soon and should be prepared.

2017 LX with 18" Tundra wheels.
And Toyo Open Country AT3

• LT275/70R18 125/122S E
• UTQG: None
• Style: Blackwall

Thank you very much in advance. I assume it is somewhere around 41 psi?

@gaijin what would the RCTIP be for these same tires on a 2021 LC?

 

[gaijin]

Me too. Going to pull the trigger soon and should be prepared.

2017 LX with 18" Tundra wheels.
And Toyo Open Country AT3

• LT275/70R18 125/122S E
• UTQG: None
• Style: Blackwall

Thank you very much in advance. I assume it is somewhere around 41 psi?

@gaijin what would the RCTIP be for these same tires on a 2021 LC?

The RCTIP for those LT275/70R18 125/112S E tires on an LC200 is 41psi F/R.

HTH

 

[gaijin]

gaijin said:
The RCTIP for those LT285/75R17/E Falken Wildpeak A/T3W tires on your LC200 is 37psi F/R. This pressure is good for all weight up to the GVWR of the vehicle.

HTH

Thank you for that!

and for airing down, you'd go to 50% of that to start? Does that change based on the conditions? I have typically aired down to 20-25psi for PNW dirt/root/light mud trails but looking to plan for Moab, should i be higher? lower?

A general rule of thumb for a starting pressure for offroad use at speeds under 20mph or so is 50% of the RCTIP. There are too many variables involved to be more specific, such as how well designed your wheels are designed to hold a bead at low pressures, how well your tires are designed to hold a bead at low pressures, soft surface or hard surface, sharp-edged obstacles or soft-edged obstacles, etc. In your case I'd suggest starting at 20psi and then adjusting up or down based on conditions.

HTH

 

[gaijin]

Pardon my ignorance, typically, how much do the pressures vary from LC200 to LX570. What are the trade-offs? I'm guessing the LX uses lower pressures to allow for a more comfortable ride. Is that accurate?

How much would a couple PSI really impact safety? I know that before people get these PSI's they have been running pressures all over the place. I know in previous vehicles I always have overinflated a bit to account for my driving habits.

Thoughts @gaijin

Good question!

First, let's get some basics out of the way so we can all speak from the same page.

Here is a pic of a TIP (Tire Information Placard) from a LC200:

And here is a pic of a TIP from an LX570:

There are a few key differences that should be noted:

- The LC200 is designated as a URJ200L where the LX570 is designated as a URJ201L. They are different platforms in the eyes of the engineers who designed them.
- Despite the GAWR's being the same for both models, the GVWR is different with the LX570 having a LOWER GVWR.
- Standard tire size is different for the two models

Some other significant differences when considering suspension components (which includes tires):

- LC200 has KDSS where LX570 does not.
- LX570 has AHC where LC200 does not.

There are many considerations that go into designing these very different suspension systems, and as to how much weight the engineers who designed these systems gave to the various performance parameters involved is unknown to anyone. However, the one overriding performance parameter for both vehicles is safety. In the specific context of your question, it is not known how much (if any) compromises were made to parameters like emergency maneuverability, braking, durability, etc. to gain better ride comfort.

The one and only artifact we have of the result of the myriad of design decisions made along the way, is the very specific Load Limit established by those engineers as the MINIMUM Load Limit required to maintain the best possible performance parameters and still be safe.

It should be no surprise that Toyota/Lexus arrived at different Load Limit requirements for these two platforms. Lucky for us, Load Limits at given inflation pressures are clearly defined in industry standards laid out by the Tire and Rim Association, Inc. (Link here: The Tire and Rim Association, Inc.). I buy their Yearbook and use it as a reference.

Toyo Tire has also published an excellent monograph on the use of the TRA Load/Inflation tables which clearly outlines the specific method of determining the RCTIP for non-stock tires (Link here: Guidelines for the Application of Load and Inflation Tables). This publication gives specific guidelines that ANYONE can use to determine the RCTIP for their specific tires on their specific vehicle - it also incorporates a lot of useful general tire info.

So... given all this, what do we need to know.

In order to find out what the RCTIP for a non-stock tire is on our vehicles, we first need to know what the tire Load Limit is as specified by the vehicle manufacturer. All the info needed to determine this is found on the TIP for each vehicle.

Using the Toyo Tire publication and the Load/Inflation tables published by the TRA, we can determine the Toyota/Lexus specified tire Load Limits as follows:

LC200:
P285/60R18 tires @33psi have a Load Limit of 2,513 Lbs.

LX570:
P285/50R20 tires @33psi have a Load Limit of 2,315 Lbs.

Now that we know the design Load Limit, it is a simple matter of looking up the tire size we want to fit on our vehicle and find the Inflation Pressure that meets (or exceeds) that Limit.

As a well-known example, lets look at the BFG KO2 in size LT285/70R17.

RCTIP for the LC200 is 40psi F/R. Any pressure lower than this would not meet the Load Limit requirement and would be underinflated.

RCTIP for the LX570 is 35psi F/R. Any pressure lower than this would not meet the Load Limit requirement and would be underinflated.

There are potentially other factors in play in determining the RCTIP such as: No LT-Metric tire can be safely operated at a pressure below 35psi, or when determining RCTIP for an ISO=Metric tire it is important to know whether the tire is SL (Standard Load) or XL (Extra Load or Reinforced), etc. That is why it is important to read the Toyo Tire monograph on the subject carefully before deciding on a pressure for your specific application.

Dangers/trade-offs for both underinflation and overinflation are well known and easily found with a Google search, but common dangers/trade-offs are: increased braking distance, less traction, etc. - in short, less safe than the RCTIP.

Of course, you are free to inflate to any pressure you want. The purpose of the RCTIP, which is derived from manufacturer and industry standards, represents the pressure that satisfies all suspension design and safety requirements of the vehicle. Go above or below the RCTIP and you run smack dab into those pesky trade-offs.

HTH

 

[gaijin]

LX570 derived RCTIP pressures are a great and safe opportunity for every 200-series variant including LCs.

Sorry. No matter how many times you tell this lie, still not true.

 

[04UZJ100]

Sorry. No matter how many times you tell this lie, still not true.

Same wheel and same tire on an LX and Cruiser. For arguments sake, stick Cruiser 18” wheel and Dunlop AT23s. What’s the RCTIP for the LX and Cruiser?

 

[gaijin]

Same wheel and same tire on an LX and Cruiser. For arguments sake, stick Cruiser 18” wheel and Dunlop AT23s. What’s the RCTIP for the LX and Cruiser?

Assuming you mean an LX570 and an LC200, and If you are talking about stock 18" size, there are two options:

For the P-Metric P285/60R18 114V SL Dunlop Grandtrek AT23:

RCTIP on the LX570 is 29psi F/R
RCTIP on the LC200 is 33psi F/R

For the ISO-Metric 285/60R18 116V SL Dunlop Grandtrek AT23:

RCTIP on the LX570 is 30psi F/R
RCTIP on the LC200 is 33psi F/R

As always, the RCTIP is the nearest whole number that is > the required Load Limit.

So... what argument are you going to make?

HTH

 

[iqbal624]

Dangers/trade-offs for both underinflation and overinflation are well known and easily found with a Google search, but common dangers/trade-offs are: increased braking distance, less traction, etc. - in short, less safe than the RCTIP.

Good question!

First, let's get some basics out of the way so we can all speak from the same page.

Here is a pic of a TIP (Tire Information Placard) from a LC200:

View attachment 2589159

And here is a pic of a TIP from an LX570:

View attachment 2589160

There are a few key differences that should be noted:

- The LC200 is designated as a URJ200L where the LX570 is designated as a URJ201L. They are different platforms in the eyes of the engineers who designed them.
- Despite the GAWR's being the same for both models, the GVWR is different with the LX570 having a LOWER GVWR.
- Standard tire size is different for the two models

Some other significant differences when considering suspension components (which includes tires):

- LC200 has KDSS where LX570 does not.
- LX570 has AHC where LC200 does not.

There are many considerations that go into designing these very different suspension systems, and as to how much weight the engineers who designed these systems gave to the various performance parameters involved is unknown to anyone. However, the one overriding performance parameter for both vehicles is safety. In the specific context of your question, it is not known how much (if any) compromises were made to parameters like emergency maneuverability, braking, durability, etc. to gain better ride comfort.

The one and only artifact we have of the result of the myriad of design decisions made along the way, is the very specific Load Limit established by those engineers as the MINIMUM Load Limit required to maintain the best possible performance parameters and still be safe.

It should be no surprise that Toyota/Lexus arrived at different Load Limit requirements for these two platforms. Lucky for us, Load Limits at given inflation pressures are clearly defined in industry standards laid out by the Tire and Rim Association, Inc. (Link here: The Tire and Rim Association, Inc.). I buy their Yearbook and use it as a reference.

Toyo Tire has also published an excellent monograph on the use of the TRA Load/Inflation tables which clearly outlines the specific method of determining the RCTIP for non-stock tires (Link here: Guidelines for the Application of Load and Inflation Tables). This publication gives specific guidelines that ANYONE can use to determine the RCTIP for their specific tires on their specific vehicle - it also incorporates a lot of useful general tire info.

So... given all this, what do we need to know.

In order to find out what the RCTIP for a non-stock tire is on our vehicles, we first need to know what the tire Load Limit is as specified by the vehicle manufacturer. All the info needed to determine this is found on the TIP for each vehicle.

Using the Toyo Tire publication and the Load/Inflation tables published by the TRA, we can determine the Toyota/Lexus specified tire Load Limits as follows:

LC200:
P285/60R18 tires @33psi have a Load Limit of 2,513 Lbs.

LX570:
P285/50R20 tires @33psi have a Load Limit of 2,315 Lbs.

Now that we know the design Load Limit, it is a simple matter of looking up the tire size we want to fit on our vehicle and find the Inflation Pressure that meets (or exceeds) that Limit.

As a well-known example, lets look at the BFG KO2 in size LT285/70R17.

RCTIP for the LC200 is 40psi F/R. Any pressure lower than this would not meet the Load Limit requirement and would be underinflated.

RCTIP for the LX570 is 35psi F/R. Any pressure lower than this would not meet the Load Limit requirement and would be underinflated.

There are potentially other factors in play in determining the RCTIP such as: No LT-Metric tire can be safely operated at a pressure below 35psi, or when determining RCTIP for an ISO=Metric tire it is important to know whether the tire is SL (Standard Load) or XL (Extra Load or Reinforced), etc. That is why it is important to read the Toyo Tire monograph on the subject carefully before deciding on a pressure for your specific application.

Dangers/trade-offs for both underinflation and overinflation are well known and easily found with a Google search, but common dangers/trade-offs are: increased braking distance, less traction, etc. - in short, less safe than the RCTIP.

Of course, you are free to inflate to any pressure you want. The purpose of the RCTIP, which is derived from manufacturer and industry standards, represents the pressure that satisfies all suspension design and safety requirements of the vehicle. Go above or below the RCTIP and you run smack dab into those pesky trade-offs.

HTH

Thank you for the detailed explanation! It really helps reinforce my thoughts around tire inflation.

Also appreciate you doing the legwork for all the people on the forum to give them the correct tire pressures for their setup.

 

[wingnutted]

Wow this thread is awesome! I did a quick search (quite possibly a poor one...) and would love a recommendation for my tires...

2013 200 Series, Falken Wildpeak AT3W 275/70/18 mounted on Tundra TRD wheels. No current changes to vehicle weight, but will be adding BudBuilt sliders in about 3 months.

 

[gaijin]

Wow this thread is awesome! I did a quick search (quite possibly a poor one...) and would love a recommendation for my tires...

2013 200 Series, Falken Wildpeak AT3W 275/70/18 mounted on Tundra TRD wheels. No current changes to vehicle weight, but will be adding BudBuilt sliders in about 3 months.

I think you are asking about the LT275/70R18 125/122S Load Range E Falken Wildpeak A/T3W tires. If so...

The RCTIP for those LT275/70R18 tires on your LC200 is 41psi F/R.

HTH

 

[wingnutted]

I think you are asking about the LT275/70R18 125/122S Load Range E Falken Wildpeak A/T3W tires. If so...

The RCTIP for those LT275/70R18 tires on your LC200 is 41psi F/R.

HTH

@gaijin You are correct, that's the specific tire. I've been running them for about 1K miles, and have been running them at 42psi, which was 100% guess based on same tire, but different size, that I was running on an 06 Tundra.

Super appreciate the validation!

 

[Ratchey]

Glad to!

The RCTIP (Recommended Cold Tire Inflation Pressure for those LT285/75R17 tires on your LX570 is 35psi F/R.

HTH

Thank you sir.