Why is picking a tire size so difficult?!

[DocMike]

35s....vs 37s
Same rig
2.5 Clayton lift -18 offset rims.

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[ryanlsmith]

I've got a Tazer in my JTR already, isn't the tire sizing feature in that supposed to help a little bit in terms of telling the tranny when to shift so that i get a bit more out of each gear?

I'd let others chime in, but afaik most of that correction is just to get the speedo right. At the end of the day, you're physically rotating larger diameter which changes the overall effective gear ratio (maybe not exactly, but not sure how else to convey it). If the circumference is longer, you travel farther on a single rotation. So on a 1:1 scale of the same speed, you require lower RPM than a smaller wheel/tire to travel the same distance (because you literally don't have to rotate the wheel as much). That sounds great on paper until it becomes too low that the engine/computer doesn't want to stall out - so it never lets you drop into 8th or even 7th. Regearing not only brings back some of the acceleration, but it lets you correct this ratio problem by essentially raising the RPMs back to near/at stock levels for a given speed and gear.

For the ridge grapplers, it looks like 35's or 37's i'm looking at the mid 12" range for width. I see their "approved rim" list, but are you saying backspacing on the stock wheels will be a problem?

I'm not sure. You may have clearance/rubbing issues at full lock. There should be fitment threads out there.

 

[AZCooWhip]

Not only 37s, but 37x13.5 here all day long and will never look back. Went with Cooper STT Pros and will do same when I replace. Yes, I did re-gear. It’s a must. Min 4:88s. 18 mpgs all day long.

I wanted the best on road manners I could get that didnt sacrifice anything for off roading.

To this day I see 35s and while they still look good, I am glad I went with the 37s. Docs comapro pics above shows it well.

 

[camodog]

Fwiw- I run BFG KO2 37s on Mopar 2” on my JTR 8 speed

a few things to note:

1. BFG sizes run smaller than advertised
2. The 8 speed auto makes it work on the stock 4.10 gearing of the rubicon
3. We live at 10k feet in elevation
4. Regear would be nice but not mandatory
5. We wheel all the time
6. If you must have the passing pep back then 4.88 or 5.13 would definitely help, we aren’t struggling, but also realize we are pushing a brick with a camper attached
7. Our speedo didn’t need a correction with the 37s (based on the local speed cameras)


pm me if you want more details. Because of of the long wb went 37 and glad we did.

TL/DR

if you do off-roading and need the extra clearance 37
If no, stay with 35

we like KO2

 

[WILL1E]

It's less about the height and about filling the wheel wells that i'm after for a more proportional look. Great input so far everyone, much appreciated!!

 

[DocMike]

37s give a better proportion in my opinion. If you are just looking at aesthetics. My photos will really help with that.

It's less about the height and about filling the wheel wells that i'm after for a more proportional look. Great input so far everyone, much appreciated!!

 

[Randonexplosion]

My 37s look smaller every day with my Clayton 2.5" diesel lift

Same tires look better on the wife's Mojave with a 2" spacer lift. Her stock wheels work just fine but the Mojave wheels have less backspacing than stock Rubicon.

 

[Lunentucker]

I chose 35s to keep the weight down, not regear, and not have poke beyond the fenders always slinging crap.

 

[bleda2002]

actually. You only get 1 inch of extra clearance. And that is assuming you have true 35 and 37 inch tires that are the exact same. Most are not. Most are some bit of a fraction below their stated tire size so if you had a 34.8 inch tire and jumped to a 36.5” tire it would only be a total of 1.7 inches difference which equals to 0.85 inches of lift also assuming you pressurize them equally.

But even with that, tire size is a diameter measurement. Not radius. Meaning a 37” tire is 1” taller but also 1” ‘lower’ than a 35. Its 2 inches of difference in total. But it only provides 1 inch of extra lift.

thats a lot of money and extra weight and cost for a pretty insignificant increase of 1” at most of ground clearance

Thats why i said 2" instead of 1". Versus stock you will gain half of 4" so 2, where as stock you will gain half of 2" so 1. If 1" is insignificant then you might as well have stayed stock as the difference between a 33 and a 35 is the same as a 37 and a 35.

As for weight and cost, that depends on rim/tire combo. Most 37's are maybe 5 lbs heavier than the equivalent 35. Every 35 doesnt weight the same, just like every 37 doesnt weight the same. You can get warn rims and general grabber atx (better version of ko2s imo) in 37's for a total of 97 pounds, or just 5 pounds over stock. You can also get something like Nitto's or kenda's for 85lb a tire in 35 then add 40+lb beadlocks. The argument that "going 35s to save weight" doesnt really add up unless you are married to a very specific tire that is exceptionally different (like load range e instead of c).

 

[AZCooWhip]

Found the pic I was looking for. Stockers then 37s w/ lift.

 

[chorky]

Thats why i said 2" instead of 1". Versus stock you will gain half of 4" so 2, where as stock you will gain half of 2" so 1. If 1" is insignificant then you might as well have stayed stock as the difference between a 33 and a 35 is the same as a 37 and a 35.

As for weight and cost, that depends on rim/tire combo. Most 37's are maybe 5 lbs heavier than the equivalent 35. Every 35 doesnt weight the same, just like every 37 doesnt weight the same. You can get warn rims and general grabber atx (better version of ko2s imo) in 37's for a total of 97 pounds, or just 5 pounds over stock.

oh ok so you were comparing stock 33’s to your 27’s. That makes sense. I thought you were comparing 35’s to 37’s in that comment, must have misread it. Thanks for clarifying that.

It's less about the height and about filling the wheel wells that i'm after for a more proportional look. Great input so far everyone, much appreciated!!

From purely a looks standpoint then yeah 37’s look better. Its pretty amazing what just 2” of tire will do. The rubicon can fit 35’s with no lift. But I prefer function over form. Hard core off roaders would benifit from 40’s as compared to 37’s. I just dont think the cost of mpg and performance justifies a 37, especially for a pavement pounder.

 

[22mojave85]

I'm thinking of 35's with 18inch Black Rhino or Fuel wheels - anyone have this setup? I've heard the Mojave does just fine with 35's and doesn't need a lift and/or leveling kit.

 

[22mojave85]

Found the pic I was looking for. Stockers then 37s w/ lift.

What wheels are these?

 

[AZCooWhip]

BLACK RHINO CHAMBER 17x8.5 5/127 ET-18 CB71.6 MATTE

 

[Sarge502]

I keep 35’s on because they do just fine off road despite what you’ll hear here, and I don’t have to deal with any of the negatives associated with making the jump to 37’s. The negatives of making that jump far outweigh the slight benefits for me.

Although I do a lot of off road and overlanding with my truck, it is also my daily driver. So for me, 35’s have many benefits and a few minor drawbacks. 37‘s OTOH, have a few benefits but many drawbacks.

It comes down to your own specific personal needs.

My personal opinion based on observation is that the vast majority of people go with 37’s just for the aesthetics. Not everyone of course but most I’d bet. I don’t blame them, they look great. But 35’s are a great compromise between performance and aesthetics.

Couldn't have said it better myself

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