I just got done lifting my jeep off the ground to check the gear ratio and it turns out I have a 4.88 rear gear or somewhere around that. I use my jeep as a daily driver and drive about 40 miles a day. I have 285/70/17's a leveling kit and its a four door 6speed. The only weight adders I have is a rugged ridge xhd steel front bumper. I have calculated my gas mileage an I am getting about 15-16 mpg but I fear the speedo hasn't been calculated to the gear change (I bought it used so idk) so I'm not sure my mpg is accurate.

 

If you really have 4.88 gears, 32inch tires and 6 speed; then you made out in the deal. Quick question... what is your rpms at 70.

Side note you might want to go up in tire size if you do have 4.88 gears.

 

Rubicon or not?

 

I have no idea what it is at 70 but if my speedo is correct I'm running about 25-2600 at 50. And no it's not a rubi.

 

what year JK do you have?

 

It's a 2008

 

thats just slightly too much gear for 33's. Would be better with 4.56's but if you plan of going 35's or 37's then youre already geared for them. Your RPM's are way too high I'm sure at 70, prob around 2900-3000 which is killing your mpg's. with a larger tire you'll get performance and those mpg's back. But youre not too bad off like I was. I had 33's on 5.38 gears and got around 11 mpg. Upped to 37's and now sit around 2500-2600 rpms at 70 and 15-16 mpg overall.

 

Sounds higher then the stock gears . I would guess u would save gas if u could bring revs down some . I'd fix it with 35s . But that's me . Cheers man

 

Yeah the build sheet says it came with 3.23's. but bigger tires sounds like a plan to me! Plus I can justify it since it will save me a little at the pump! First off I think I need to get a procal to make sure my speedo is correct for the gears.