So I’m bring a topic back to life.
I always thought I’d stop at 35’s but recently made some upgrades to my JKU that have me questioning 37’s. I’m looking at 2 sizes of tires from 2 different manufacturers. ( I’m not going to name them because I don’t want this to be a brand argument.)
I’ve read the threads and everyone says with 37’s you “have to upgrade shafts” and “you will need to upgrade this and that” and “you will lose performance”. The question I have is…why??

This is why I ask. I am currently running the tires size 295/70R18.. roughly a 34.6 x 11.5 that weighs in at a whopping 82 lbs.. The tire I was considering going to 37x12.5R18/D Actual Size 36.8 x 12.5 weighs in at only 72 lbs. So I ask, wouldn’t my current tire create more wear & tear and do more damage to my MPG and on road performance than the 37’s?

Also since I'm technically running a "34" if I were on a 35 going to a 37 only adds an inch and a half or so.. I don't see how that could be the breaking point.. could it?

Side question.. can I get 37’s on my specs in my signature?

 

Tire weight is most of it.The reasoning for people giving long list of upgrades to go with 37s is they are basing it on the average tire weight of that size. The only other factor is the contact patch of the tire when aired down. This is all my opinion though. I believe stock shafts should be fine as long as your not going out to bounce your rig.

 

What you will need to upgrade depends on how you use your jeep. If you only do moderate trails and don't spin your tires you should be okay. If you use lockers and do a lot of Rock crawling you will need to make some upgrades. I have broken chromoly shafts with my 37s. There is a lot more to wear On your rig than just tire weight. The larger diameter tire requires more force to turn. Tell us a little more about how you use your jeep.

 

as mentioned, there is more to tire size than just weight and really, you need to stop looking at the actual tire size when discussing what can and or should be done. certainly, when guys like me talk about 37's vs. 35's, we're strictly talking about what's writen on the sidewall.

 

This is what I was wondering.. is it the size or more to it (ie friction and rotational force). Many of the previous threads I searched said "37s means more upgrades" but logic tells me there's more to it. I wheel moderate trails in colorado couple times a season. Haven't gotten in to heavy rock crawling...yet.

I know there isn't an exact equation that = axle failure but am trying to determine all of the factors, a lot of which are left off previous threads...
Thanks..this helps.

 

There is alot that goes into it. Spinning wheels catching traction, bond up wheel trying to force it through, bouncing up obstacles, amount of throttle you use, as you can see the list keeps going and going are chromoly shafts great? Of course are you going to break your stock one driving down a dirt road probably not. It all depends on your driving style and how hard you are on your equipment.

 

Sorry WOL. I'm not quite getting what you're trying to say...please elaborate....