Tire Pressure recommendation (3 Viewers)

[indycole]

Obviously you are free to run your tires at whatever pressure you want, but do know that it's not unheard of for car insurance companies to deny claims due to "defective" tires that simply aren't inflated to the correct pressure as per the industry guidelines. It just seems like an unnecessary risk to me.

 

[eizenjin91]

OK, if we are talking hypothetically, let's all get on thge same page so we might actually produce something meaningful with all this.

First, @eizenjin91 you know you are over the allowable max weight for your vehicle - and that your weight is distributed too far forward. Let's assume we're not going to "fix" any of that. So ... yes, your tires probably need a little more pressure to support that weight.

@indycole has a pretty good idea, but I don't think it needs to be that complicated, and the numbers don't work for @eizenjin91 LT285/75R17 tires.

Hypothetically, since we are talking about an increase in weight less than 5% (7385 pounds to 7720 pounds), we may be able to safely assume that any "safety margin" built in to the stock numbers does not have to increase proportionately within this small percentage increase. This might be an easier way to go:

(Gross Weight - GVWR) / 4(tires) = Amount additional Load Limit required.

(7720 - 7385) / 4 = 84 pounds/tire

Load Limit at your Recommended Cold Tire Inflation Pressure of 37psi = 2301 pounds

New Load Limit for 7720 pound Gross Weight = 2301 pounds + 84 pounds = 2385 pounds/tire

From the Load/Inflation tables for the LT285/75R17 tires:

- 35psi => 2215 pounds
- 40psi => 2430 pounds

| (2430 - 2215) / (40 - 35) = 43 pounds per 1psi

- 35psi => 2215 pounds
- 36psi => 2258 pounds
- 37psi => 2301 pounds [Your Recommended Cold Tire Inflation Pressure for stock GVWR of 7385 pounds]
- 38psi => 2344 pounds
- 39psi => 2387 pounds [Your Hypothetical Cold Tire Inflation Pressure for a GVW of 7720 pounds]

Hypothetically, of course

HTH

Thank you and Indycole both so much!! I hate math and I’m absolutely horrible at it makes my damn head hurt. I really appreciate all the info/help y’all have given. If I hypothetically had those cat scale numbers I faked I would hypothetically run my tires at 39psi now.

I am very surprised by saying I have my weight too far forward. The ONLY thing I have in the front is a bumper and winch with 2 lights. I am by myslf in the truck (I weigh 190). My 2nd row is completely gone with only a 15 gallon water tank in place. Everything else is stored in the drawers in back with rear bumper tire carrier. I have a roof tent which is only thing I can figure would put weight forward??

Indycole I know we have relatively similar trucks have you weighed yours? How was your weight split?

Adding a 40 gallon aux fuel tank in the spare tire location will be interesting. I may have to see if I can replace some skids or sliders with aluminum.

 

[TonyP]

You're about 400# heavier than I am with armor and packed for a weekend of camping.

 

[gaijin]

Thank you and Indycole both so much!! I hate math and I’m absolutely horrible at it makes my damn head hurt. I really appreciate all the info/help y’all have given. If I hypothetically had those cat scale numbers I faked I would hypothetically run my tires at 39psi now.

I am very surprised by saying I have my weight too far forward. The ONLY thing I have in the front is a bumper and winch with 2 lights. I am by myslf in the truck (I weigh 190). My 2nd row is completely gone with only a 15 gallon water tank in place. Everything else is stored in the drawers in back with rear bumper tire carrier. I have a roof tent which is only thing I can figure would put weight forward??

Indycole I know we have relatively similar trucks have you weighed yours? How was your weight split?

Adding a 40 gallon aux fuel tank in the spare tire location will be interesting. I may have to see if I can replace some skids or sliders with aluminum.

If you look at the door placard with all the info:

You can find the following important info:

GVWR (Gross Vehicle Weight Rating) 7385LB
GAWR FRT (Gross Axle Weight Rating Front) 3595LB
GAWR RR (Gross Axle Weight Rating Rear) 4300 LB

Compare these to the corresponding numbers from your CAT Scale record (good on you for weighing your truck, BTW):

Gross 7720LB
Steer Axle 3780LB
Drive Axle 3940LB

Don't worry, I'm not going to make you do any math (well, not a lot), but we can see the following:

Gross 7720LB - GVWR 7385LB = 335LB Over [This means the total weight of your vehicle is 335LB over the recommended max]
Steer Axle 3780LB - GAWR FRT 3595LB = 185LB Over [This means the amount of weight on your front axle is 185LB over the recommended max]
Drive Axle 3940LB - GAWR RR 4300LB = -360LB Under [This means the amount of weight on your rear axle is 360LB under the recommended max]

That's why I suggest your truck's weight is distributed too far forward than recommended.

Clear as mud, right?

HTH

 

[indycole]

Indycole I know we have relatively similar trucks have you weighed yours? How was your weight split?

This is from a while back. I'll weigh again once the new bumper is on.

 

[eizenjin91]

You're about 400# heavier than I am with armor and packed for a weekend of camping.

Interesting TonyP thanks. Right now I’m packed for 10 days camping. When I get back from this trip I’ll empty out the truck and see what it weighs with just truck bumpers sliders skids drawers tires. Then look at how much gear I’m adding.

If you look at the door placard with all the info:

You can find the following important info:

GVWR (Gross Vehicle Weight Rating) 7385LB
GAWR FRT (Gross Axle Weight Rating Front) 3595LB
GAWR RR (Gross Axle Weight Rating Rear) 4300 LB

Compare these to the corresponding numbers from your CAT Scale record (good on you for weighing your truck, BTW):

Gross 7720LB
Steer Axle 3780LB
Drive Axle 3940LB

Don't worry, I'm not going to make you do any math (well, not a lot), but we can see the following:

Gross 7720LB - GVWR 7385LB = 335LB Over [This means the total weight of your vehicle is 335LB over the recommended max]
Steer Axle 3780LB - GAWR FRT 3595LB = 185LB Over [This means the amount of weight on your front axle is 185LB over the recommended max]
Drive Axle 3940LB - GAWR RR 4300LB = -360LB Under [This means the amount of weight on your rear axle is 360LB under the recommended max]

That's why I suggest your truck's weight is distributed too far forward than recommended.

Clear as mud, right?

HTH

You’re a wealth of knowledge buddy thanks! I’ll defintrly have to look in to what I’ve got that’s putting that much weight forward I know dual batteries and arb bumper/warm winch but I wouldn’t imagine that much. Apparently I need to spend more time looking at m door sticker.

This is from a while back. I'll weigh again once the new bumper is on.

Was that with a front bumper and winch? With the LRA Aux tank? Interesting you’re in the exact same position more or less that i am. Thanks for posting for me to compare.

 

[indycole]

Was that with a front bumper and winch? With the LRA Aux tank? Interesting you’re in the exact same position more or less that i am. Thanks for posting for me to compare.

No front bumper. No rear bumper. No winch. No prototype off-road-use only aux tank.

I did have James Baroud RTT, two spare tires (second was on a 35 lb wilco carrier), 10 gal fuel, 15 gal water, camera equipment, fishing equipment, some target shooting stuff, hiking/backpacking gear, full camping loadout, lots of tools, recovery gear, luggage and personal items for my wife and I for a 3 wk trip, and probably some firewood as well.

 

[TonyP]

Interesting TonyP thanks. Right now I’m packed for 10 days camping. When I get back from this trip I’ll empty out the truck and see what it weighs with just truck bumpers sliders skids drawers tires. Then look at how much gear I’m adding.


You’re a wealth of knowledge buddy thanks! I’ll defintrly have to look in to what I’ve got that’s putting that much weight forward I know dual batteries and arb bumper/warm winch but I wouldn’t imagine that much. Apparently I need to spend more time looking at m door sticker.



Was that with a front bumper and winch? With the LRA Aux tank? Interesting you’re in the exact same position more or less that i am. Thanks for posting for me to compare.

Word.
I'm planning on weighing again before I cross the boarder in a couple of weeks.
Guessing I'll be a fair bit heavier and over GVWR.
I'm sure I'll burst into flames and open up the gates of hell like this thread is implying when you're a few pounds over.

 

[Markuson]

Word.
I'm planning on weighing again before I cross the boarder in a couple of weeks.
Guessing I'll be a fair bit heavier and over GVWR.
I'm sure I'll burst into flames and open up the gates of hell like this thread is implying when you're a few pounds over.

I'll bring an extra fire extinguisher... (note the Baja palm trees...)

 

[eizenjin91]

Gaijin master tire ninja not sure if you're still around but I have one more reccomendation I'd like from you if you are. 11,900lb vehicle 37x12.50R17 Mickey Thompson Baja ATZ P3. What's your reccomended road pressure? Thanks

 

[Markuson]

Gaijin master tire ninja not sure if you're still around but I have one more reccomendation I'd like from you if you are. 11,900lb vehicle 37x12.50R17 Mickey Thompson Baja ATZ P3. What's your reccomended road pressure? Thanks

He’s a 200/570 ninja only...
You will find he keeps pretty strictly within the bounds of this forum.

 

[gaijin]

Gaijin master tire ninja not sure if you're still around but I have one more reccomendation I'd like from you if you are. 11,900lb vehicle 37x12.50R17 Mickey Thompson Baja ATZ P3. What's your reccomended road pressure? Thanks

You're more than 4,000 pounds overweight! No recommendation for that from me ...

 

[MilkmanVX]

@gaijin -thanks for all the info and your time on this issue. I don't think I saw a recommendation for a Nitto Trail Grappler LT285/65r18 on a 2018 LC200.

 

[gaijin]

@gaijin -thanks for all the info and your time on this issue. I don't think I saw a recommendation for a Nitto Trail Grappler LT285/65r18 on a 2018 LC200.

The Recommended Cold Tire Inflation Pressure is 42psi F/R.

HTH

 

[MilkmanVX]

The Recommended Cold Tire Inflation Pressure is 42psi F/R.

HTH

Thank you sir!

 

[gaijin]

Thank you sir!

You're very welcome. Always glad to help.

 

[REZolution]

@gaijin Thanks in advance for the help. What would be the recommended cold tire pressure for Nitto Ridge Grappler LT275 /70 R18 (2017 LC200)?

 

[gaijin]

@gaijin Thanks in advance for the help. What would be the recommended cold tire pressure for Nitto Ridge Grappler LT275 /70 R18 (2017 LC200)?

The Recommended Cold Tire Inflation Pressure is 41psi F/R.

You're welcome!

 

[not0ny]

Any recommendations for a 2017 toyota tacoma (double cab short bed) running falken wildpeaks p285/70/17?

 

[gaijin]

Any recommendations for a 2017 toyota tacoma (double cab short bed) running falken wildpeaks p285/70/17?

Nope. LC200/LX570 only.