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2012 Jeep Wrangler Sahara Unlimited. Four door soft top. Cooper 33 tires. Figuring probably between 35 and 40 PSI for rear tire pressure. The trailer on towing a single axle 3200 lb camper trailer. What do you guys think? I'm at the tire pressure not the weight of my trailer because I know it's pretty close to the max weight for my Jeep
 

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that sounds good.
You can easily adjust the pressure down on the road.


Lower pressure gives a better ride when running empty, but you will get more sidewall flex when towing.
 

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Two methods I know of.
One is to watch tire pressures. You should see around a 10 percent increase in tire pressure from cold to hot. So if you set them at 40 psi cold and when driving down the road they increase to 44 psi your pressures are right for the load they are carrying. But if they increase to 46 psi you might want to increase the cold pressure as lower pressures generate more heat which causes more pressure increase. If they only increased from 40 psi to 42 psi that would tell you that you can safely lower the cold pressure a little to get a better ride.
Another way is what they call "The Chalk Test". That is where you use chalk to mark a stripe across the face of the tire and adjust your pressures to where it wears that chalk stripe evenly off the face of the tire. That shows you that your tire is evenly wearing and not wearing too much in the middle of the tire (over inflated) or on the edges of the tire (under inflated).
 

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2012 Jeep Wrangler Sahara Unlimited. Four door soft top. Cooper 33 tires. Figuring probably between 35 and 40 PSI for rear tire pressure. The trailer on towing a single axle 3200 lb camper trailer. What do you guys think? I'm at the tire pressure not the weight of my trailer because I know it's pretty close to the max weight for my Jeep
IMO you're thinking about right. I'd start at 37 (cold) myself.

That's a lot of trailer for a Jeep, so IMO make sure your "wet" weight isn't much more and pay close attention to the tongue weight. I like to put my trailer (and Jeep for that matter) on a scale before I do long trips just to verify my weight.

As a reminder in 2012 the 3500 pound weight limit is for 4 door Jeeps with 3.73 gears. A 2012 Sahara with 3.21 gears has a 1,000 pound rating. Also pay attention to the frontal area limitations when towing a camper :thumb:

https://www.wranglerforum.com/f274/the-jk-towing-thread-2007-2018-owners-manual-specs-2325363.html#post33862717

Good luck!!
 

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Discussion Starter #5
I know I'm at my max. I made sure I had right gears. I've towed many trailers just none with my jeep. I made sure the trailer had brakes and i set up my jeep for trailer brakes too. I'm heading to Radium BC from Calgary, I know it'll be a tough tow. I have the "torque " app so I can monitor my coolant and trans temps. $15 for the bluetooth adapter and $5 for the app. It's a really handy app, that's for sure
 

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Best is to look up a tire inflation table for the type of tires you have (load C, D or E), like https://static1.1.sqspcdn.com/static/f/589830/23447320/1378330097907/Discount+Tire+inflation.pdf

Take 50% of your Jeep's loaded weight, add the trailer tongue weight (10-15% of full trailer weight) and divide that by 2 to get the weight each tire will have to carry.
You looks this up in a tire load table and you'll get the minimum pressure required. Then add a safety margin, like 25%.

Example: my Jeep (5,600 Lbs with driver) + 300 Lbs tongue weight (3,000 Lbs trailer x 10%)

5600 / 2 + 300 = 3,100 Lbs on rear axle or 1,550 per tire.

My tires (Dick Cepek, D 119-rated) can carry that at about 27 psi.
But at 35 psi they have a rating of 1,955 Lbs; that's 25% above what's needed and that's the pressure I use when towing.

Note: also keep an eye on your GCWR. In the example above, I'd be over the GCWR of 8,326 Lbs. I can tow up to 2,726 Lbs if I carry nothing in the Jeep...
 
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