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Chalk Test.

For what its worth, my Toyo Open Country MT's (Load Range E) Like 24psi front and 22psi rear. This is on a Frontier though with no load in the bed.

The reason a chalk test is important is because Vehicle Weight, Tire Size, Rim Size, Tire composition, Load Rating, etc, ALL play a role in proper tire pressure.
 

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I am currently running my LT265/75R16 Cooper ST/Maxx "E" load-rated tires at 35psi, the same pressure listed on the door plate for the OEM tires. A quicky chalk test showed that to be close (and based upon the TRA Load Rating Chart, 35-40 psi appeared to be close to the "theoretical" proper pressure for "E" tires on a rig the weight of an Xterra), but I still need to do a bit of adjusting now that the weather is dry. My guess is that the optimal pressure will probably be around 32 psi.

Your results may be different because you are running a slightly wider tire on the same width rim, but 35 psi is a good place to start.

[For frame of reference, when I ran "C" load-rated 35x12.50R15 BFG MTs mounted on 10" rims on a Jeep CJ-7, the chalk test showed 26 psi to be the optimum street pressure.]
 

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oh god...... the can of worms has been re-opened
 

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Chalk Test.

For what its worth, my Toyo Open Country MT's (Load Range E) Like 24psi front and 22psi rear. This is on a Frontier though with no load in the bed.

The reason a chalk test is important is because Vehicle Weight, Tire Size, Rim Size, Tire composition, Load Rating, etc, ALL play a role in proper tire pressure.
Wouldn't your sidewalls be flexing at that pressure? I know the chalk test involves a smooth contact patch but not at the expense of sidewall flex

And I know with my duratracs and km2s there is noticeable sidewall flex when I go under 30.


Chalk test or not I can't see how running tires 11-15 psi below the sticker with load range e is the best idea. I would imagine this contributes to worse mileage and more wear.
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Wouldn't your sidewalls be flexing at that pressure? I know the chalk test involves a smooth contact patch but not at the expense of sidewall flex

And I know with my duratracs and km2s there is noticeable sidewall flex when I go under 30.


Chalk test or not I can't see how running tires 11-15 psi below the sticker with load range e is the best idea. I would imagine this contributes to worse mileage and more wear.
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No change in ride height going from 34 psi down to 24 with these tires. I don't notice any real sidewall changes unless it starts dipping below 18. At 34 the tires are way too stiff, you feel every bump in the road. It literally feels like low profile tires on 20" rims.

I don't understand your correlation between tire wear and psi when a proper chalk test on all 4 tires was what determined proper tire pressure. Sometimes you just need to go with the facts.
The sticker on the door is only applicable to the size tires listed there. Once you change tire size (or even same tire size but different load range) you can literally throw that sticker in the trash as it means absolutely nothing.

This tire is at 22 psi, you can see there is no noticeable sidewall flex even though it is fully stuffed into the wheel well (most of the weight is on that tire, front wheel is even off the ground.).
 

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I run 38 PSI in mine. I have 285/70/R17 BFG KM2's. I just got them about a week ago and they are okay. I haven't taken it off road yet but will next Saturday.
 

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I run my 295/75 R16 load D DynoPros Mts at 35-36 psi. Over 40psi yeilds a very rough drive, everytime i go to discounttire for rebalance/rotate they always air them up to 50 and it feels like im going to rattle right off the road.
 

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I run my 295/75 R16 load D DynoPros Mts at 35-36 psi. Over 40psi yeilds a very rough drive, everytime i go to discounttire for rebalance/rotate they always air them up to 50 and it feels like im going to rattle right off the road.

Same here. Door says 36 and that's what I use and have perfect tire wear and a comfortable ride.


Sent from AutoGuide.com App
 
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