LT265/65R18/E KO2 vs 265/65R18/SL Wildpeaks - sidewall strenght?

DaveInDenver

Middle Income Semi-Redneck
Btw. You will almost always need considerably more pressure moving from P-metric tires to LT tires. The P-metric tires simply handle more weight at a certain pressure than same size LT tires do.
Based on the standard derating that would match my 40ish psi finding. IOW, a load index of 111 SL P265/70R16 at 29 psi (e.g. 2,216 lbs) would fall between 40 and 45 psi for a 123 LT265/75R16 E/10 then. So my chalk and butt I guess aren't too badly calibrated for Falkens! I was running my BFG under pressure though it seems. :)
 

Bayou Boy

Adventurer
Based on the standard derating that would match my 40ish psi finding. IOW, a load index of 111S P265/70R16 at 29 psi (e.g. 2,216 lbs) would fall between 40 and 45 psi for a 121S LT265/75R16 E/10 then. So my chalk and butt I guess aren't too badly calibrated for Falkens! I was running my BFG under pressure though it seems. :)

Good deal. The Toyo instruction do tell you to extrapolate between 5psi increments but the rise is not linear across the entire range.

I ended up typing the chart for my tires into the Notes app on my phone. I run my 37s at a pretty low pressure for daily driving for ride quality and then increase them for the load. With a 4000# payload rating I have a lot of difference between empty and loaded.


Sent from my iPhone using Tapatalk
 

DaveInDenver

Middle Income Semi-Redneck
Good deal. The Toyo instruction do tell you to extrapolate between 5psi increments but the rise is not linear across the entire range.

I ended up typing the chart for my tires into the Notes app on my phone. I run my 37s at a pretty low pressure for daily driving for ride quality and then increase them for the load. With a 4000# payload rating I have a lot of difference between empty and loaded.


Sent from my iPhone using Tapatalk
That is part of the root I surmise why I found ~35 psi on the BFG to be more tolerable. I'm never pushing the payload limits of E-range tires on my Tacoma and perhaps the 3 ply sidewalls were enough more stiff than 2 ply to make a difference in ride quality.
 

Rovertrader

Supporting Sponsor
Check the Cooper A/T3 also. I love the Falken but have the same issue in that size for the LR3, and just ordered the Cooper, so no feedback yet, sorry. But they do have the E rating...
 

kga1978

Active member
Check the Cooper A/T3 also. I love the Falken but have the same issue in that size for the LR3, and just ordered the Cooper, so no feedback yet, sorry. But they do have the E rating...

Yeah, was wondering about the Cooper's too. Please report back if you don't mind ;).

As for getting the Falken's in an E rated, I unfortunately can't go to a 275 tire - it's just a tiny bit too big for the GC to fit without rubbing. I think I have dropped the idea of the KO2s at this point - just doesn't seem to make sense for 99% of what I do with the car.
 

Peter_n_Margaret

Adventurer
I run in the Sierra (e.g., Coyote Flat) keep blowing out my sidewall.
Why do these tyres fail?
Stakes can cause failure, so can over inflation or under inflation and overloading.
A thicker or stiffer sidewall may not be the answer.
Cheers,
Peter
OKA196 motorhome
 

Martinjmpr

Wiffleball Batter
As for getting the Falken's in an E rated, I unfortunately can't go to a 275 tire - it's just a tiny bit too big for the GC to fit without rubbing. I think I have dropped the idea of the KO2s at this point - just doesn't seem to make sense for 99% of what I do with the car.

A small lift or spacers might fix the fit issue. The thing is, your Grand Cherokee is a car and you're trying to get truck tires to fit it. As I said, the 275/65/18 size offers a LOT of LT tire options, much more than you will find on smaller, lower-aspect-ratio tires like you're running now.

Also I'd echo the poster above. If you're blowing out sidewalls I'd try to figure out why rather than just "assume" it's because you're running P rated tires rather than LTs. LT's may not fix the problem and then the only difference would be that now you have a more expensive tire to replace. ;)
 

kga1978

Active member
Why do these tyres fail?
Yeah, good question, and I wish I had the answer. Coyote Flat is known for eating tires, and it has happened to me whether I have been running street pressure (33psi) or my more typical 'off-road' pressure of 22psi. The car isn't too heavy - only running my camping gear, recovery gear, and an awning (no RTT, etc. - I sleep in the back). That said, it's a GC, so not exactly a light vehicle... ;-).

Will 17" wheels fit on your Jeep?
I wish! But sadly no - because of my brakes, I can't go below a 18" tire.

The thing is, your Grand Cherokee is a car and you're trying to get truck tires to fit it
Very true - and as mentioned, I'm definitely not told on getting LT tires. I like the idea of a stronger side wall, but for most other driving LTs wouldn't be preferable and they're pretty overkill for a GC.

I'll probably wait around a little to see if any new tires come out, but overall I'm leaning towards the Falken's (P-rated) and then we'll see how they fare on the trail - if nothing else, they should be better than my stock GY adventures.
 

douglastic

Member
May be old news, but Wildpeak come in XL (kind of a mid-way between SL and E) in your original size: 265/60R18

I have them on my LR3 due to the need for XL minimum rating

I also have the same issue wanting 265/65R18 in E for the Wildpeak, but I asked them and they have no plans to make one
 

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