I know this topic has been discussed a hundred times in a thousand ways, but I can't seem to find what I'm looking for by searching old posts...
Will swapping to a 33" tire on my Rubicon noticeably effect my spedometer, gas milage and acceleration? I'm torn between going with the stock bfg's or stepping up to a 33" with a body lift.
If you've got 33's, I'd love your input.
Thanks, Nathan

 

Check out this website

1010tires.com/Tiresizecalculator.asp

 

no, the change won't be that significant. if you want to correct your speedo, i would recommend getting an aev procal as they are cheap and will allow you to set your speedo accordingly.

 

The change is minor....I am running 33x12.50R17's and I am off by maybe 3-5km/hr (1-2MPH) from my stock 32 Duellers. This is measuring with a GPS unit vs my speedo. I am running 3:73 and 6spd and noticed very little difference in acceleration at stock settings. With your Rubicon and 4:10 gearing and 33's you won't notice any difference in acceration!

You may want to invest in a Superchips as it has helped with acceleration and power going up mountain passes. Go with a wider 33 and you will love the look and stance over the stock BFG M/T's.!

 

You could go with teraflex leveling kit for about the same price as a body kit. I think it would look better too. I am just not a fan of body lifts.

 

I did the exact same tire size and wheel setup you are asking about, but did a TF 2.5" BB initially (with Spidertrax wheel spacers). I could not tell any difference performance-wise or mileage-wise from the change. I can still accelerate up long grades in 6th gear. In all honesty, the BFG MT KM2 (285/70/17) I swapped are not significantly larger than the stock BFG MT. I like them a lot better, though. The TF BB is long gone (most of it, anyway) with an OME standard spring suspension in it's place, but the tires are still there. After rotating the tires a few times, I can't see how anyone does it with larger than 33" tires. I can barely lift those suckers, and I'm not getting any younger...

 

Funny you should ask ! I came on the forum today to see about the same thing. I have had new tires and rims for about a week and it seems like:
1. I've lost about 2 MGP (according to the avg on the dash computer)
2. have trouble keeping my Jeep cruising at 80 and
3. am downshifting more than before in order to take inclines (sometimes mild)
I have a 6 spd with 3:73 gears, stock tires were 255/75/17 (actual diameter 32.1) on 17 x 7.5 rims.
Went to 255/85/16 (actual diameter 33.1) on 16 x 8 rims

When I am doing 80, my RPMs are at about 2,750, whereas before it would be right at 2,500.

Would a Superchips correct this ?

 

Get a Superchip!@ Everyone has different opinions.

 

I think it may depend on whether you're running automatic or manual, what gears you have, etc. I've got an auto 4-door with 3.73s and I noticed changes in all the categories you mentioned when I put my 33s on. Lost some MPG, definitely felt even more sluggish accelerating from a dead stop and yes, it throws your speedo off by a couple mph. If your speedo was set for 32" tires, might not be as noticeable, but I have an X that came with the 31" Wranglers. I would definitely recommend getting the Superchips Flashpaq. You'll be able to recalibrate the speedo and just running on the stock 87 tune will help with some of the lost mpg and give better throttle response than what you had stock. At least that's been my experience.

 

i ran 33/11.5/17s on my 2 door manual rubicon for about 8 months. speedo was off anywhere from 3-5 km/hr depending on speed. didnt notice much of a difference in gearing with my 4.10s. if anything it was affected more at highway speeds than in 4lo and crawling. gas mileage went down but nothing too serious. hope this helps.