I am looking to purchase the Rough Country 2.5" lift kit and 33" tires. I currently have the stock 31" tires that came with my Sahara. Couple of questons...

1) Do I need to change out the gears (or anything else) or can I just add these mods to the stock setup?

2) Anyone know the estimated imapact on MPG? I get 18MPG with my current set up and am just curious to know how it will change. Not that it really matters bc I will do it anyway<s>

 

SJBissett, the Sahara actually comes stock with 32" tires, given that here are some responses
1) Are you running the stock gears in the back or did you upgrade to the Dana 44 with the 4.10 gears? If you are running the D44 with the 4.10s you likely will not notice much.

2) There should be little impact on your MPG.

...Most importantly...Use the search function, there is more information on this site to shake a stick at. Gearing and tires has been covered numerous times with numerous opinions. Look through those and use it to formulate your own opinion

 

SJBissett, the Sahara actually comes stock with 32" tires, given that here are some responses
1) Are you running the stock gears in the back or did you upgrade to the Dana 44 with the 4.10 gears? If you are running the D44 with the 4.10s you likely will not notice much.

2) There should be little impact on your MPG.

...Most importantly...Use the search function, there is more information on this site to shake a stick at. Gearing and tires has been covered numerous times with numerous opinions. Look through those and use it to formulate your own opinion

Congrats on the JK

 

Thanks for the quick response. I did use the search function and there was so much info it was a bit hard for this newbie to translate. Anyway, I just looked at my sticker and I do have the Dana 44 Heavy Duty rear axle and heavy duty suspension with gas shocks.

 

That being said, you may want to look into a gear upgrade...but that is not cheap to be honest. It is probably cheaper to by the JK Rubicon axle with the 4.10s already installed, install it yourself, than it is to regear. I think most shops will charge you anywhere from $900-$1500 out the door for a regear. The axle runs about that match and you have added some beef to your rear end....

 

I was editing my posting when you responded. I'm assuming I do not have to do this since I do have the upgrade??

 

You can put 33's !!! with or without a lift ( but lift will help with articulation )

The only problem may come with what your stock gearing is ( towing package or not and what trans or what year )

It helps to have a SIGNATURE so we know what yr ,trans,tow pack, etc .....for anyone to answer !!

( READ MY SIGNATURE) I put 33 on stock rim and only lost a little bit (18- 16) , but when I put steel rock crawlin rims I lost alot (18- 14.5)

The Mickey Thompson MTZ is only 1/2 inch taller than my stock tire(32.3 inch/32.8 inch) but much wider and heavier and the steel rim compared to aluminum ( you can guess )

So I put my stock tire /rim combo back on until I go wheelin so I have no more complaints with 17.6 to 18.3 as an average city / highway

Your welcome to check out my gallery link I have pics of pre lift with 33's and post lift with 33's and post lift with stock tire/wheel

Good luck and happy JEEPIN

 

I am getting about 15 - 16 mpg daily city (keep the fwy speed 75 or lower). I have 5.13 gears and 35"s with a 3.5" lift and it seems to me that I have dropped about 15-20% on the MPG. I had 4.10's prior to the 5.13's, with an auto trans the jeep did not like being in overdrive on the freeway. The slightest change in grade caused the jeep to downshift to 3rd. Now with the 5.13's that problem has gone away. If you do to 35's or larger and you have a manual do 4.88's, if you have an auto do 5.13's. With 33's I would do the mods and check it out. If you have 4.10's you probably won't have a problem, especially considering the Rubi's come with 32's stock.

 

Wow, lots of surprises in this thread. Changing from aluminum to steel wheels cost 2.5 MPG (or 3.5 mpg in brackets). Adding a rear Rubi axle is likely cheaper than a full price re gear for both axles? But, both axles need to end up with the same ratio +- .01:1 or so. An axle swap for $1200 or so is a great deal, but not if you can't use 4wd or need another Rubi axle (or re-gear) for the front.

As you may have found searching for "mpg" won't work because of the search tool limitations. If you use Google, you can search jk-forum.com, but you will find 30 threads talking mostly about crazy and unbelievable gas mileage noted on the liar of a dash readout. Doing real research on JK gas mileage is really a difficult task.

I'll take my own crazy guess. I think you will lose 1.5 to 2 mpg. In the city you will get almost the same, since the wind resistance has less of an effect. The faster you go the more of an impact it will have. There is logic behind this guess, but in the end it is just a guess like everyone else.

 

I lost 3-4 mpg from stock alum rims (245/75/16 on it) to rock crawler steel w/33's.

Now I thought the JK was a little low on power already, so now I have to spend some cash on power gain to at least get back to what I had. Maybe cold air and exhaust might get me back to where I was.