Actual tire diameter - a scam?

[PyrPatriot]

Looks like the life a way forum already did an outstanding summary

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[jimbom]

My Falken MTs (285/70/17s) calculate to be a diameter of 32.7. On the Jeep, inflated at 34 psi, they are just a hair over 32 inches tall, but 33 inches measured across. Close enough for me.

With variables in load, psi, rim width, etc, there really is no definitive diameter.

 

[jimbom]

Looks like the life a way forum already did an outstanding summary

I don't know what life a way is. A link, perhaps?

 

[Digger70]

I don't know what life a way is. A link, perhaps?

He means the [Banned Site] Jeep forum. way a life

 

[PyrPatriot]

So by the math, I should be seeing a 1.3” lift over my factory configuration. The oem tires are calculated to be 30.5” by revolutions per mile, and the Falken 35s are to be 33.1”. That is a 2.6” difference, half being 1.3”. In reality only 1” of clearance increase at the pumpkin, going from a factory 10” to 11”

Ironically if I had gone with 37” Geolandars I would be 5.2” greater in calculated diameter from oem, and thus 2.6” in mathematical lift height

 

[Mr. Wuf]

My 37" Ironman All Country mud terrains measure 35.75" on my Jeep.

 

[PyrPatriot]

Measured my 35s at about 30psi. Just shy of 34”. Acceptable.

My 255/75/17 were right at 31” measured. So I should see a 2” ‘increase in clearance. BUT, my pumpkins only went up by 1”, being now 11” from ground when OEM spec is 10”. Even that 1” has helped me scrape a lot less on trails. But even if I measured the 35s at 33.5”, I should still be getting an extra 1/2” to 3/4” increase in height from pumpkin.


can anyone with stock sport wheels and tires measure ground to pumpkin difference on their JT?

 

[RHINO79]

Taking a tape measure to my 255/75/17 (aka 33s) I get 31”

Actually, so called 32s

 

[Overland_Dreamrz]

When I changed to Falken AT4W's (35"), I had to set my Tazer to 34.98" in order to have my GPS and Speedometer identical. I'd consider that 0.02" of difference inconsequential.

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