KO2 tire pressure

[JTJeep]

I just put a set of new KO2’s 285/75R17 on my 2021 Sport S, same tires that come stock on a Rubicon. If someone would take a look at the recommended TP inside the drivers door of their Rubicon and reply, it would be appreciated.

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[GATORB8]

37, but the actual size on the Rubicons is 285/70R17

 

[JTJeep]

37, but the actual size on the Rubicons is 285/70R17

Thanks, and I stand corrected on the tire size.

 

[Rhinebeck01]

@JTJeep
Rubicons 285/70R17 .... Door sticker says 37# psi, but you really do not want to run them at that..

You'll do far far better running at 32# in the Summer in Maryland and 34# in the Winter. 37# is way to much, especially in the Summer and well, even in the Winter...

Reason for the higher in the Winter is because when temps fall at night, etc., psi will drop below 32# and you will get an EVIC light warning.

DO check/change psi in the early morning before vehicle use and or Sun hitting tires... Use a decent tire gauge. Do not rely/trust to much, the onboard psi reading.

With psi as I mention steering will better as well as ride in general.

Research "Chalk Test" if you want to really get into the psi and your JL thing...

Also, remember your steering column is adjustable...

Adjust the steering column, so that you are not reaching for the steering wheel.

You want a bend in your arm. IF, you have to reach, your arms get tired easier/ faster and you will be causing the JL to wander thanks to those stretched out fatigued arms..

.

 

[AcesandEights]

Since BFG makes both sizes, the 285/75/17 are an "E" rated tire and you'll want to run a different pressure. The 285/70/17 are a "C" rated tire. I run between 29 - 34, depending. I don't like running that low, but when it is cold, when there are cold swings the cold temp is 29 and by afternoon they are 31 - 32 psi. Next time I have the compressor out, I'll air them to 34.

 

[GATORB8]

Since BFG makes both sizes, the 285/75/17 are an "E" rated tire and you'll want to run a different pressure. The 285/70/17 are a "C" rated tire. I run between 29 - 34, depending. I don't like running that low, but when it is cold, when there are cold swings the cold temp is 29 and by afternoon they are 31 - 32 psi. Next time I have the compressor out, I'll air them to 34.

I find the pressure differences pretty interesting. Tiresize.com has a great pressure converter. Although the Es in this case can carry a lot more load, it's at such a high pressure, that there's only a 2 PSI difference in the calcs.

 

[AcesandEights]

Makes me wonder, how do you know when you're running low pressure that causes heat, and therefor damage to the sidewall? Is low pressure based on the "placard" in the vehicle, or the tire?

If the placard says 65 psi in a full-size truck and you're running the same tire in a Jeep with a 37 psi placard, does the tire know not to heat up, or is the weight of the vehicle keeping the amount of friction comparable between the two vehicles, therefor the tire doesn't heat up?

 

[JTJeep]

My original post was incorrect, size is 285/70R17 C, OEM tires.

 

[mferrara91]

I run mine at 37.

 

[WilhelmSR]

@JTJeep
Rubicons 285/70R17 .... Door sticker says 37# psi, but you really do not want to run them at that..

You'll do far far better running at 32# in the Summer in Maryland and 34# in the Winter. 37# is way to much, especially in the Summer and well, even in the Winter...

Reason for the higher in the Winter is because when temps fall at night, etc., psi will drop below 32# and you will get an EVIC light warning.

DO check/change psi in the early morning before vehicle use and or Sun hitting tires... Use a decent tire gauge. Do not rely/trust to much, the onboard psi reading.

With psi as I mention steering will better as well as ride in general.

Research "Chalk Test" if you want to really get into the psi and your JL thing...

Also, remember your steering column is adjustable...

Adjust the steering column, so that you are not reaching for the steering wheel.

You want a bend in your arm. IF, you have to reach, your arms get tired easier/ faster and you will be causing the JL to wander thanks to those stretched out fatigued arms..

.

To give clarification to those not familiar with MD weather. It runs around 90's with decent humidity in the summer and around 20's in the winter. Hope that helps

 

[dshark1]

I run my KO”2s @ #32. They heat up on the highway to #34 ,, on those extra hot & humid days which is always in Florida. They can go up to #35

 

[entropy]

I run my 33 falkens at 35 cold. seems to be the sweet spot for these.

 

[GATORB8]

Makes me wonder, how do you know when you're running low pressure that causes heat, and therefor damage to the sidewall? Is low pressure based on the "placard" in the vehicle, or the tire?

If the placard says 65 psi in a full-size truck and you're running the same tire in a Jeep with a 37 psi placard, does the tire know not to heat up, or is the weight of the vehicle keeping the amount of friction comparable between the two vehicles, therefor the tire doesn't heat up?

I’ve had tires really hot on a track and was always more concerned about rolling them to far onto the sidewall than the sidewall temp.

I always look at it as the manufacturer rates it so that the contact patch is correct holding the max load at the max PSI on the tire. The less the load, the less the required PSI to maintain the contact patch.

 

[AcesandEights]

The manufacturer of the vehicle puts the placard in the vehicle based on the "stock" tire, so how would you know from a 285/70/17 C to a 285/75/17 E whether to run different pressure, or whether you were running under-inflated, causing excessive heat ? Does it not matter what tire is on the vehicle, they all should be run at the same pressure?

Enquiring minds...

 

[GATORB8]

The manufacturer of the vehicle puts the placard in the vehicle based on the "stock" tire, so how would you know from a 285/70/17 C to a 285/75/17 E whether to run different pressure, or whether you were running under-inflated, causing excessive heat ? Does it not matter what tire is on the vehicle, they all should be run at the same pressure?

Enquiring minds...

No, at the same weight capacity. Which may be a different pressure

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