215/85R16 Tires?

[WheelNut]

Hey Guys,

Curious if anyone has ever run this tire size on their KJ? This is about the tallest and narrowest tire I can find for a 16" rim. With what I've read about clearance challenges for the KJ I wonder if this tire could be a good way to avoid rubbing while still getting a little bit of extra tire diameter. The narrow width might be good for highway fuel economy too?

Related question- what rips the fender flares off Liberty's? Tires that are large in diameter, or is it a combo of width and diameter? I'd really like to get larger tires without having to add longer bumpstops so that I can maintain lots of suspension bump stroke for good performance when smashing over large pot holes in the road.

 

[p14175]

I looked at that tire size since it would work fine with the OME lift (about 1.5 inches), but I couldn't find an MT tire that I liked that wasn't E rated.

 

[tommudd]

Several things wrong with this size
FIRST; they are 30.5 inches tall, unless you have a2.5 inch lift they will rub bad in front
SECOND; They are all way over rated for a KJ ( 8/10 ply ) and will ride very rough
So this is a bad way to get height

On to flares , what tears them off mainly is people not running bumpstops, way too wide of wheels with bad backspacing

With the tires you want to run you would need to run bumpstops ( well you have to anyways )

 

[XWrench3]

Just my humble opinion, but the little fuel savings (if any*) is probably not worth altering the way your Jeep handles in an EMERGENCY! they do make fuel saver tires, that have less rolling resistance than regular tires. and will not alter the way your Liberty handles.

The issue as see it, is will you save enough money by gaining 1-3 mpg to offset the cost (or extra cost if your Jeep actually NEEDS tires) to actually save you any real money.

As I see it, it's a lot like a dog chasing its own tail. you can spend a lot of time and energy for little to no real gain. no one I know has ever bought a 4wd vehicle. dragging, pushing and turning a boat load of extra gears, shafts, bearings and seals, not to mention 600-700 pounds of extra weight. with aerodynamics resembling that of a brick to save money on gas.

Seriously, go enjoy your Jeep doing what it was designed for. you will have a LOT more fun. and its a lot easier to justify spending $ on fun than on just commuting. commuting is what they build a Toyota Prius' for!


* taller tires do make for less rpm's at any given speed. BUT because of the extra diameter, the engine will have to make more torque to turn them. extra torque requires more fuel.

 

[tommudd]

would require more fuel to get down the road with that size and weight of the tire

 

[WheelNut]

You guys don't run E rated/"10 ply" A/T tires? All the groups I'm on around here recommend E rated for gravel/offroad/back country driving to help improve durability and lessen the chance of a flat. NVH is surely the trade off. A 'D' load rating is the next step down. Is there a big difference in puncture protection between an E and a D tire?

XWrench3- When you say the performance of the vehicle will be compromised what context are you saying that in? I was thinking something like a Firestone Destination X/T 215/85R16 vs 245/75R16. Both are the same height/diameter, so its just the width that is changing. Fuel economy isn't a big determining factor, but it could be a bonus to get slightly better mileage while also having less chance of rubbing at full steering lock. I'd like to go towards a taller A/T tire, and I know that these will have worse fuel economy than a standard sized highway tire and they will make the vehicle worse in emergency maneuvers due to the higher CoG and taller, floppier, sidewalls.

 

[tommudd]

Your thoughts that you should run a 10 ply is way out there
You will not get better fuel mileage going to that size, the height and weight will knock you down for sure
PLUS the fact you need a 2.5 inch lift

 

[WheelNut]

I'm just repeating 10 ply advice I've heard from other in my area. Tom you have any thoughts on what load ratings are appropriate for what conditions on a Liberty?
I hear what you're saying about fuel mileage. Throw it out the window as a consideration- understood.
I know I need a lift. That is obvious.

 

[tommudd]

I've ran nothing more than 6 plys and some just regular passenger on the last 8 Jeeps I've owned ( last 31 years ) and have wheeled all over West Virginia, Virginia, Kentucky , Indiana etc with no issues

As far as punctures I have seen as many 10 ply as I have 6 or even passenger rated ones get something going through them
To be properly inflated a 10 ply will be 80 lbs of air or so so a very hard ride and no need on a light bodied KJ

Plus it looks funny I think, like its on stilts

 

[bgcarl02]

The advice here for freshly graded north maine woods roads is also 8 or 10 ply as well. So I get what you're saying. I ran a set of 215 85 16 10 ply ats. They were fine. Didn't notice handling issues or anything. Toms right, look nice from side, fat guy on stilts from the rear or front. Lol. I've ran two sets of 10 ply 245 75 16 since those. Probably won't go back simply due to looks.

 

[tommudd]

Yes people think that if they run 10 ply they are way better
If you check closely most have only 4-6 actual plies in the construction of the tire , not 10 ply

 

[WheelNut]

I found this last week. "Ply ratings" are just a carry over from the by-gone era of bias ply tires. The letter coded load rating system is what is used in modern tires and isn't necessarily correlated to the number of layers in the tire's carcass. Seems like puncture protection is simply a function of design choices on the tire makers part and not necessarily the load rating. Seems like the advice being doled out by the locals here is rather misguided.
https://www.tirebuyer.com/education/tire-ply-rating

Also, Tom: E rated tires are only meant to run at high pressure if you are carrying a heavy load. They can be run at high pressures to handle heavy loads, and the tire pressure should correspond to the load that tire will see. Tire rack has some info on this here:
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=195
An E rated tire will likely ride worse than a lighter rated tire due to its stronger construction that can handle more pressure. Inflating an E rated tire to its's max pressure with your vehicle at it's normal weight is no good.

 

[tommudd]

Fully aware of the above, 20 years managing tire stores for Goodyear etc taught me a few things

and I started out in the "bias ply " era

 

[WheelNut]

...

run a 10 ply at say the ratings that are on your Liberty door and see what happens

Care to elaborate on what will happen if one were to run E rated tires at the door sticker pressures on a Liberty? (Assuming said E rated tires are factory sized, since if the tires are a different size they will need a different pressure)

 

[lfhoward]

Care to elaborate on what will happen if one were to run E rated tires at the door sticker pressures on a Liberty? (Assuming said E rated tires are factory sized, since if the tires are a different size they will need a different pressure)

I run 265/75R16 KO2’s (E rated) at 36 psi. They are fine. Yes, there are some slight mileage losses compared to the C rated Duratracs I used to run, but they are comfortable tires over bumps and on the highway. When I tow heavy loads I can increase the pressure in the rear tires, and I can air them all down when off road. I’m happy with them. Are E rated tires overkill for a Liberty? Sure, probably. Is it an issue? No.