Anyone running 2012 4dr with auto tranny 3.73 gears and 35" tires, if so what kind of gas milage are you getting city and highway? I'm more conserned about Highway.

Any input is welcome.

 

I've got the same setup as u...35 nitto trail grapplers. I'm getting terrible mileage, but I'm also doing 70-75 MPH. Between 12-15 MPG highway. Ive noticed that the jeep has almost no power in O/D (5th gear) and believe this is what's killing my MPG. However, if I drive 60-65 MPH (if youre from NJ you know that's nearly impossible...everyone flys) I get 15+ MPG.

 

average speed on the parkway or turnpike is like 80MPH....ridiculous for us box driving jeepers

 

When doing 65 mph your getting about 15+, how much is the plus? That's almost what I'm getting with my 2011 3.8 with O/D off at 65 mph.

 

The more I read about this new penstar engine, ya it is more powerful but the same complaints are coming to light. Power in certain bands, MPG , Torque. But going 65-70 this flying brick will get just what you are getting. I doubt a desiel will get much better at that speed.

 

Mine is a 2 door with 33s and I'm getting 18.5 in my daily driving which is mostly around the suburbs. My 08 got about 16.5. I've got no complaints about power or torque. The Pentastar dramatically changes the character of the JK. That doesn't mean it's fast - it just means it's tossable and more fun.

 

X2... we drive a box on wheels. If so worried, change gears like I am in the process off, get a flashpaq, and if you want a CAI and catback...thats all you're gonna get to boost any performance where it would be night and day.... unless you wanna get a supercharger.

 

Just put lower gears and it will feel like a race car till 40mph and lots of fun too , untill it pops out of gear and you see first gear on the highway behind you. haha. You are slowly hearing about the same old tranny problems too. You think that would have been addressed all ready. Not enough complaints to get them to address and fix them. sorry to go off thread.

 

I hear you. I am old and slow so going slow is no problem. ha. But my buddy has a 12 unlimited no order so I will get a chance to see the difference. But this is my one and only Jeep and it will be most likely hemi-fied to compensate. I will go crate engine tranny . Then redo , upgrade refurbish everthing to new.

 

I drive 42 miles each way to work five days a week. If the 2012 was getting 3 to 4 mpg more with this setup I was thinking about trading in my 2011. 85 miles a day with 3-4 mpg adds up over the years.

From what I'm reading I think ill just regear, then maybe in a few year SC the 3.8L