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  #1  
Old January 21st, 2021, 10:59
MiWiAu MiWiAu is offline
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XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

TL/DR: If I went with E load range tires for my XJ, how much would I compromise off-road traction and on-road ride quality to gain sidewall durability vs going with a Standard/P load range? Is it worth the tradeoff?

Hey all,
I know tire questions are never-ending, and I have more of them. I’m new to the Jeep/off-road scene, so I don’t have a background in off-road other than some m/c trail riding, but I have been trying to research and these are the questions I’m still left with.

Vehicle Background
I have a 98 XJ, and I’m looking to upgrade to 31” tires to fit a set of 16x7 Jeep Icon wheels. It looks like my main options are a 265/70R16 (my strong preference due to the extra width) or a 245/75R16.

My intent is to build this thing primarily as an overlanding vehicle and be able to eat up some highway miles on the way to some more scenic trails. I’m in SE Wisconsin, and not sure of many (any?) trail options that are local to me, so travel will be required. I may want to do some more moderate stuff at the off-road parks, but I’m looking to make it an adequate all-around performer, not specialized for any single type of off-road. It is definitely a project vehicle and NOT my primary mode of transportation, so that affords me some flexibility, but ultimately, I want a good balance of on/off road performance.

The questions…
Is there a good way to determine whether or not a tire is designed to run aired down without contacting a manufacturer and/or is there a list of currently available tires that fit this criterion? One recommendation I found in my research was to purchase a tire specifically designed to run aired down. The description for the BFG KO2 mentions “additional traction…during “aired down” off-road driving,” but they are the only ones I ran across that specifically mention airing down.

With the added sidewall stiffness of an E load rating, do you really even see much benefit in airing these down on a vehicle as light as an XJ? It seems that the benefit to airing down is to increase the contact patch and improve conformability to terrain, but if the carcass doesn’t flex due to a super stiff sidewall, how big of a compromise is the E load rating to traction? For Standard/P load range vs E, it seems that the tradeoff here is potentially conformability/traction when aired down vs sidewall durability.

Are there any Standard/P rated tires for lighter vehicles that are known for good sidewall durability off-road that provide less of a compromise to on-road ride quality? I see the Goodyear Wrangler All-Terrain has Kevlar and is available in both standard and E load ranges. It would be nice to save the extra weight from an E tire, if the standards won’t leave me stranded.

If I run a 265 tire on a 7” rim, any suggestions on lowest tire pressure to run to prevent my tire from coming off the bead? For most of the 265 tires I've found, 7" is the minimum "recommended" rim width. Obviously, I wouldn’t be running bead locks with the Icons. 😊
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  #2  
Old January 21st, 2021, 11:43
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Tim_MN Tim_MN is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

I don't know any reason why a good quality tire cannot be run aired down off-road. All tires benefit from airing down for trail usage. On pavement, NEVER drive very far or very fast on aired down tires.

There are lots of choices for C rated tires especially if you go with 15" rims. IMO P metric tires are for cars and pavement, a E rated tires are simply too stiff for a light weight 4x4.


I sold off the 16" rims and tires that were on my XJ and replaced them with 15" rims and 31x10.5x15 tires. I have a set of off-road tires and a set tires for daily driving/winter. The main reason for the switch was the 16" tire cost and lack of choices in 16" tires.
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Last edited by Tim_MN; January 22nd, 2021 at 05:01.
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Old January 21st, 2021, 12:01
RCP Phx RCP Phx is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

I buy Goodyear Duratracs just because they available in "C"'s vs most 16" "D"'s or "E"'s.
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Old January 21st, 2021, 12:21
Unclewolverine Unclewolverine is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Running the mail on very bad roads i would love to run e's like all the carriers running jks but the only e's for 15's are trailer use only and I don't really want to go to the expense of switching over to 16 inch rims. On the mail route c's only last 20k before they are so thin you're patching rock punctures every other day.
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Old January 21st, 2021, 14:04
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jeep ride jeep ride is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

I have hankook all terrian at2 31x10.50x15 mounted on 15x7 cragar d windows good tires
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Old January 21st, 2021, 15:49
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Tim_MN Tim_MN is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

The load rating of tires does not directly equate to puncture resistance. If someone wants more puncture resistant tires they should look for Kevlar sidewall reinforcement or extra steel belts in the sidewalls.

Load range D or E tires will be heavier, affecting the ride quality, acceleration and gas mpg's, may be more difficult to balance correctly, and depending on the tire design likely will not be as flexible as a C range tire.


I think for the usage MiWiAu is proposing BFG A/T KO2 would be a good all-around tire choice, and GoodYear Wrangler MT/R with Kevlar would the choice for extra puncture resistance. I have not punctured any tires in MN or WI off-roading, but have punctured a few in CO and UT, the rocks seem to be extra sharp there.
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Old January 21st, 2021, 16:40
MiWiAu MiWiAu is offline
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XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Thanks for the feedback, gents! I'm still in the planning phase and not quite ready to pull the trigger on tires, but this is one of those decisions that is a bit spendy, and I will ponder for some time - maybe change my mind a time or ten as well. 🤣

I really love the style of the 16" Icons, so I'm set on staying with those, so at the end of the day I'm willing to compromise to maintain the styling.

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Old January 21st, 2021, 16:47
MiWiAu MiWiAu is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Quote:
Originally Posted by RCP Phx View Post
I buy Goodyear Duratracs just because they available in "C"'s vs most 16" "D"'s or "E"'s.
I looked these up in 265/70R16 it was showing standard load rating. I might not find a C rated tire in the metric sizing. Thanks for the suggestion!

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Old January 21st, 2021, 17:15
RCP Phx RCP Phx is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Been running then for over 10yrs, tried everything else and will never change now!
https://www.goodyear.com/en-US/tires...ac/sizes-specs
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Old January 21st, 2021, 17:17
RCP Phx RCP Phx is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Quote:
Originally Posted by RCP Phx View Post
Been running then for over 10yrs, tried everything else and will never change now!
https://www.goodyear.com/en-US/tires...ac/sizes-specs
Seventh one down, LT265/75/16
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Old January 21st, 2021, 18:25
MiWiAu MiWiAu is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Quote:
Originally Posted by RCP Phx View Post
Seventh one down, LT265/75/16
Roger that. I saw those, but the 265/75-16 is closer to a 32", correct? I was looking at the 70 profile, but definitely not as many options there..

What lift are you running? I was looking at the OME 3.5, but wanted to try to keep trimming to a minimum.

Thanks!

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Old January 21st, 2021, 18:40
RCP Phx RCP Phx is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

I'm at 5.5" and my 265's do come in as a 32-11.50's so you would need a smaller size but that would also depend on your backspacing. I'm running 4.5" of BS.
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Old January 21st, 2021, 21:52
Black1990jeep Black1990jeep is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Before the Jeep I did off roading in a Vanagon (2wd!) The Vanagon uses light truck tires (LT) and requires a fairly high road pressure. These are street tires. But when off roading, even on hard packed dirt roads, I will air them down. This gave better traction climbing rocks, and helps considerably so reduce the wash road vibration on the dirt roads.

So yes, street tires can be aired down for improved traction and ride off road.
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Old January 21st, 2021, 22:00
Black1990jeep Black1990jeep is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Per my Oasis Off Road tire computer...

245/75R16 at a 4000 lbs weight you may safely go down to 14 psi, 3000 lbs weight and you can go to 12 psi

265/75R16 at 4000 lbs you may go to 12 psi , 3000 lbs you can go to 10 psi.

Note do not exceed 20 mph. For each 10 mph above 20 mph add 3 psi to the above minimum pressures.
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Old January 22nd, 2021, 08:55
MiWiAu MiWiAu is offline
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Re: XJ 16" Wheel / 31" Tires - Best Balance of On/Off Road Perfromance?

Quote:
Originally Posted by RCP Phx View Post
I'm at 5.5" and my 265's do come in as a 32-11.50's so you would need a smaller size but that would also depend on your backspacing. I'm running 4.5" of BS.
Nice! This forum needs a "like" button. I measured my back spacing at 5.25", but I'm okay adding spacers as required.

Quote:
Originally Posted by Black1990jeep View Post
Per my Oasis Off Road tire computer...

245/75R16 at a 4000 lbs weight you may safely go down to 14 psi, 3000 lbs weight and you can go to 12 psi

265/75R16 at 4000 lbs you may go to 12 psi , 3000 lbs you can go to 10 psi.

Note do not exceed 20 mph. For each 10 mph above 20 mph add 3 psi to the above minimum pressures.
Thanks for the calcs! Are they specifically load based pressures, or does it also consider bead retention?
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