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How much lower after airdown?

nU7OuxIx

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I have a stock JLUR with the KO2 LT285/70R17C BSW Off-Road tires. I bought a rooftop tent and know that it would be tight trying to get it out of the garage. I measured it and it's about 12.5" from the roof to the top of the garage door. The RTT is 12.5" high, without the rack.

Without having to try this experiment myself, I'm guessing somebody here probably knows the answer. Do you know how much height I could gain if I drop the tires to 10 psi?

Thanks in advanced!
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Reinen

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Given that you need to drop the height of the rack in addition to clearing the tent, and I don't know how tall the rack is, I think you're putting that tent on outside. If you do clear the tent, it will be with near flat tires.
 

omnitonic

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285mm * 0.70 = 199.5mm = 7.85". That's the height of one sidewall. On an LT load range C, I would guess you could drop maybe 4-5", but I just kind of closed one eye and pulled that number out my ass. LT sidewalls are pretty stiff by design.
 
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nU7OuxIx

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285mm * 0.70 = 199.5mm = 7.85". That's the height of one sidewall. On an LT load range C, I would guess you could drop maybe 4-5", but I just kind of closed one eye and pulled that number out my ass. LT sidewalls are pretty stiff by design.
If it does drop 4", there's a chance I may be able to fit it inside the garage. Maybe I should get off my butt and actually try it if it's that much. I thought it would maybe drop it a half inch at the most.

I have an idea about rigging something up so I can load/unload it outside, but it would be 10 times easier and nicer to have a hoist in the garage.
 

omnitonic

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If it does drop 4", there's a chance I may be able to fit it inside the garage. Maybe I should get off my butt and actually try it if it's that much. I thought it would maybe drop it a half inch at the most.
I don't actually have any experience doing the limbo with load range C LT tires, but I did spend four years as a tire man during the last recession. The math on the sidewall height is solid. You've probably got 2" of tread and compressed carcass that you can't squish through any amount of airing down, but I feel pretty confident you should be able to get at least 4" with no trouble. Go slow. Be careful. I can't be held legally liable if you break your door, or your Jeep, because only your eyeballs can tell you whether or not it's really going to work. With that disclaimer in place, I think it will probably work.
 

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nU7OuxIx

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Well, I aired down to about 10psi and if anybody is wondering, it didn't lower the Jeep nowhere close to what I was thinking. I would say that I maybe gained about a half inch, if that.

Maybe it's because the tires were new, but it didn't do a whole lot like I thought it would.
 

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I run 15 lbs of air Sahara 18" tires, when towing my boat on a very sandy beach and by sight it's not noticeable, never measured?

Go Jeep!!!
 
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nU7OuxIx

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I run 15 lbs of air Sahara 18" tires, when towing my boat on a very sandy beach and by sight it's not noticeable, never measured?

Go Jeep!!!
I was surprised....maybe the tires don't flex much, who knows. They are ko2's and I was expecting it to look like a flat tire...but nope. Unless it has to settle, it didn't look flat like I thought it would.
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