I had a 2" OME lift on my 100 series with 275/70/18 BFG KO's 33" tire's and it looked perfectly balanced. I want the same thing for the 2015 LX570. Thanks for being the test case
New LX 570 ... Method NV + K02 sizing inquiry (1 Viewer)
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gaijin
GOLD Star
For the record, and so there is no confusion about what I recommended, this was my recommendation:
Your stock P285/50R20 tires @ 33psi have a Load Limit of 2,315 pounds/tire.
Your new P275/60R20 tires will only require 28psi to reach a Load Limit of 2,341 pounds/tire.
Michelin recommended 29psi because they are too lazy to do the math - the Load/Inflation tables only list 26, 29 or 32psi so they chose the closest to what it should be, 29psi, which yields a Load Limit of 2,381 pounds/tire which is more than you need.
Don't understand why you want to run yours at 30psi, which is overinflated, but it's your choice.
HTH
Would that be the same for BFG A/T KO2's 275/60/20? 30-32 psi
gaijin
GOLD Star
No.
The P275/60R20 tires have a recommended Cold Tire Inflation Pressure of 28psi Front/Rear.
The LT275/60R20 BFG A/T KO2's have a recommended Cold Tire Inflation Pressure of 40psi Front/Rear.
Both recommended pressures are for the LX570.
HTH
Thanks
What did you do about the spare? Can you still use the OEM 285/50/20 for emergency situations? If you had to buy a new spare did the 275/60/20 fit in the spare location?
What would be the correct tire pressure for an LX 570 with BFG AT/KO2's 275/55/20? Thanks
gaijin
GOLD Star
Your 2015 LX570 came stock with P285/50R20 111V tires and a Recommended Cold Tire Inflation Pressure of 33psi F/R.
The BFGoodrich All-Terrain T/A KO2 LT275/55R20 115/112S Load Range D tires would have a Recommended Cold Tire Inflation Pressure of 46psi F/R to achieve the same Load Limit as the stock tires.
HTH
Damn, won't they ride like a rock? How low can you run them on a LX570 and they still be safe? Also if I am using the OEM spare for emergencies and have it inflated to 36 won't the tpms monitoring go off? With the BFG's inflated to 46?
Gaijin, I get it now, did some research.
gaijin
GOLD Star
Will they ride like a rock? Well, the tire's sidewall "spring rate" will certainly be stiffer with 46psi than the stock wheels with 33psi, but because of construction differences between the tires I would expect the increased stiffness would not be as much as you think.
How low can you run them and still be safe? Easy answer - 46psi. Ask yourself, how low can you run the stock tires and still be safe? Wouldn't the answer be 33psi? Before all the "Boo Birds" chime in, I am not talking about off-road aired down conditions, I am talking about on-road use. For off-road, my 50% rule of thumb would still apply for use at reduced speed.
TPMS? I can only offer an educated guess. Let's assume you have 4 tires @46psi and 1 tire @33psi. You perform the TPMS reset procedure with those pressures. My understanding is the TPMS will trigger a low tire warning when ANY tire goes below 25% of the set value OF THAT TIRE. So, in this case, the TPMS would trigger if any one of the 4 tires set to 46psi goes below 34.5psi or if the 1 tire set to 33psi goes below 24.75psi. So no, the TPMS would not trigger if you have reset the TPMS with the BFG's @46psi and your spare @33psi.
Here are the relevant number to keep in mind:
Stock P-Metric tires @33psi have a Load Limit of 2,315 pounds/tire.
When fitting LT-Metric tires to an originally P-Metric application, the Load Limit for the LT-Metric tires should be reduced by 10% (2,315 / 1.1 = 2,105 pounds/tire)
The LT-Metric BFG's @46psi have a Load Limit of 2,270 pounds/tire, more than the required 2,105. This is rounded up to the nearest whole psi value which exceeds the required minimum. At 45psi, the BFG's Load Limit is only 2,085 pounds/tire which is less than the required minimum of 2,105 pounds.
Short, serious bottom line: Anything under 46psi for the BFG's on your LX and you are underinflated.
HTH
gaijin
GOLD Star
I appreciate the education, at first I just could not get it?? Then the light finally went off, looked at an inflation chart that showed what you are saying and I finally got it. The scary part is on my old 100 series I was running BFG AT/KO's 33". At 33 psi, which now I realize was dangerous and I probably aged those tire's. After this realization I was going to forget the BFG option for my LX570 but based on your post that the BFG AT/KO2 at 46psi would not be much different ride wise then the P tire's at 34-35 psi. You have also made the Tmps monitor a non-issue. Thanks
now i too am concerned that I am running the wrong pressure on my new 285-65-18 Falcon wild peaks. I've been having trouble getting an accurate reading on the pressure, gauge says 40, tpms says 32. I was hoping to get them to 42 psi but now I'm not sure what the best number is.
gaijin
GOLD Star
The Recommended Cold Tire Inflation Pressure for the LT285/65R18E 125/122S Falken WILDPEAK A/T3W tires is 42psi F/R for your 2010 LC200.
After setting the tire pressures to 42psi when the tires are cold, perform the TPMS reset procedure:
After the TPMS is reset, the values in the TPMS display should be within 1psi of the pressures you set in the tires. If your TPMS is still showing 32psi when the tires were inflated to 42psi, then you have a problem either with your tire gauge (most likely) or with your TPMS. It is important you determine the source of the error to avoid incorrect pressures in your tires. I'd beg, borrow or steal another tire pressure gauge (or two) and see if they read the same as your gauge.
HTH
I'm questioning this assumption. I get that for truck that was originally fitted with LT, that fitting a P-Metric tire, would require a de-rating of said P tire, since it wasn't built with the heavier duty and higher center of gravity application in mind.
I'm not sure that it works the other way. Inherently an LT tire is built stronger than a P tire. So my intuition is that the LT tire needs no de-rating. And that 46 PSI hence is too high.
I of course defer to you as the expert. This just seemed off to me.
gaijin
GOLD Star
I refer you to page 11 of the following document for a simple explanation: https://toyo-arhxo0vh6d1oh9i0c.stac...ication_of_load_inflation_tables_20170203.pdf
It is not an assumption, it is a convention. Our Land Cruisers are Light Trucks. When Light Trucks are fitted with a P-Metric tire, the Load Limit must be increased by 10% (factor of 1.1). This means that the Recommended Cold Tire Inflation Pressure on the door jamb for the P-Metric tires on our Light Trucks yields a Load Limit which is 10% high. When fitting an LT-Metric tire to a Light Truck originally fitted with a P-Metric tire, we must reduce the manufacturer recommended Load Limit by 10%.
In SWUtah's case above, we reduced the recommended P-Metric Load Limit of 2,315 pounds by 10% (2,315/1.1) to 2,105 pounds. We then found an inflation pressure for the LT-Metric tire that met or exceeded the reduced Load Limit of 2,105 pounds.
We are not de-rating the LT tire as you suggest, but rather removing the de-rating that was applied to the P-Metric tire. The end result is that on the Land Cruiser, a P-Metric tire must be inflated to carry 10% more load than an LT-Metric tire.
Clear as mud, right?
HTH
Edit to add: To be clear, no, 46psi is not too high
gaijin
GOLD Star
Thanks for entertaining my question and taking the time to school me (in a good way). Much appreciated.
You're very welcome!
Always glad to be able to give a little back.You're very welcome!
Gaijin
What about LT275/60r20D BFG KO2 119/116 s. On a 2018 Lexus LX570 three row.
