Tire Size Options 2011 JK 3.8 Auto

Hey guys,

I'm running a 2011 3.8 JK with auto tranny on a 2.5 lift..

Just wondering which tire sizes would give me most bang for my buck.

A lot of guys here run 285/70s but they seem to be getting quite horrible fuel consumption.
So I'm thinking, why not just go slightly bigger and get 305/70s and deal with the same horrible fuel consumption but have the joy of bigger tires.

However, are the 305s not getting close to regear territory? Cause if I end up having to regear a sloth Jeep I'd rather just go all out with 35s..
But I'd prefer to save the cash from regearing for winch, lighting etc..

At same time, I work abroad for most of the year, so my JK sits around most of the time. So I guess if you look at the bigger picture, my fuel bill over the period of a year will be hardly anything.

So that's it I guess..

Will appreciate all the input I can get
 

wayoflife

Administrator
Staff member
A 35x12.50R17 tire has a true measurement of about 33". A 285/70R17 has a true measurement just shy of 33" and a 305/70R17 has a true measurement that is just a bit over 33". In other words, they are all about the same size tire and with that, I personally would regear to 4.88 to help restore your power back to stock.
 

JDDK

Member
I have an 08jku 3.8 auto with 3in and regeared to 4.88s. I was running Nitto terras at 285/70 and just went to 35x12.5 km2s. They are a couple inches taller (measured side by side)and look noticeably bigger and now the look is perfect! It stills has good power with the 4.88s. X's2 for Eddie's advice. You will be stoked on this setup!!!
 

cmireles

Member
Hey guys,

I'm running a 2011 3.8 JK with auto tranny on a 2.5 lift..

Just wondering which tire sizes would give me most bang for my buck.

A lot of guys here run 285/70s but they seem to be getting quite horrible fuel consumption.
So I'm thinking, why not just go slightly bigger and get 305/70s and deal with the same horrible fuel consumption but have the joy of bigger tires.

However, are the 305s not getting close to regear territory? Cause if I end up having to regear a sloth Jeep I'd rather just go all out with 35s..
But I'd prefer to save the cash from regearing for winch, lighting etc..

At same time, I work abroad for most of the year, so my JK sits around most of the time. So I guess if you look at the bigger picture, my fuel bill over the period of a year will be hardly anything.

So that's it I guess..

Will appreciate all the input I can get

In all honesty, my 285/70/17 Terra's with 3.21 gears on my 2 door don't get that bad of gas mileage. I'm not trying to say don't go 35s (or 315s) and a regear though, since personally that is what I'll be doing this late spring.
 
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