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Hey guys.. I'm looking for someone to suggest the best cpu chip and modification for gas mileage and running 35"s with a 3" lift on my 2017 unlimited Sahara
 

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Hey guys.. I'm looking for someone to suggest the best cpu chip and modification for gas mileage and running 35"s with a 3" lift on my 2017 unlimited Sahara
Are you looking for a performance tune or just simple recalibration to correct for tires? Superchips may make the flashpaq for a 17 but I believe you have to send in your ecm. Im sure others that have used it can speak to its effectiveness.
 

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You can't do a performance tune for a 2015+ as far as I know without swapping ECU's and losing your warranty.

You're not going to get the power or mpg back until you re-gear the axles for your 35's. You'll still need a flashpaq or AEV pro-cal to program the jeep for the tires and gear change too.

Get 4.88 gears and it'll be like a new jeep.
 

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Yeah, a tune isn't gonna give you much performance. You can get a Superchips Flashcal to correct your speedometer/odometer. As for MPG's, well honestly you're SOL. It's a Jeep with the aerodynamics of a brick.
 

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Discussion Starter #6
Ok thank you guys.. I was going to buy the 599$ trail dash 2 but not now. I'll use the extra money to re gear it. What brand gears would your recommend? I don't want to lose my warranty...
 
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I would get a SuperChips flashcal to recalibrate for tire size and it will change your shift points. Depending what you use your jeep for DD, light off road hard core rock crawling would depend on the gears you put in it. If it is 98% on road I would suggest 4.56 gears with 35s. Also depends if your jeep is a manual or automatic. We recomend Revolution gears. Let us know if we can help you out at all. As far as your warranty if you change anything on your jeep it is at the dealer descretion weather or not they fix it. Find a mod friendly dealer in your area and you shouldnt have any issues.

-JP
 

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Unless you are doing the gears yourself, you probably want to use the gears whomever is installing the gears uses, as you want them to warranty the gears. I don't think there is much difference between different brands of gears, except price.
If your Jeep has not already been calibrated for the 35s, meaning making the speedo read correctly, you should do that, especially if it is an auto. But putting 35s on a Jeep makes it slower, even with the speedo corrected. No "tune" is going to fix that. But with an auto, if the speedo isn't correct your shift points also aren't correct so it will be even slower than it should be.
Don't get me wrong, I like bigger tires, just making the point that bigger tires tend to suck up hp.
As mentioned by JP, 4.56 or 4.88 tend to be the two main options for best gearing with 35s. Different factors like auto or manual, along with whether it is a Rubicon or not, and how do you use it, affect which way to go. Autos are more tolerant of taller gearing in my opinion. With a manual if the gearing is too tall you can't go slow enough without slipping the clutch. That usually doesn't end well. Rubicons have a short 4 low ratio in the transfer case, so they can get away with taller gearing and still be able to go slow in the slow stuff. If you don't do much really slow stuff, being able to go that slow may not help.
One last thing about gears. Shorter gears make your Jeep accelerate quicker. If you want your Jeep to be quicker, I would lean more towards the 4.88s. If that is not an issue and you are more concerned about highway cruising and fuel mileage 4.56 might be good, all else being equal.
 

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Everything I've read says the superchips (or any other programmer) won't change the shift logic of the 5 speed auto. It has it's own TCM. That why I like the AEV procal- set the dip switches, plug it in, and jeep is programed for tires, gears, and TPMS thresholds.

Nothing will overcome the driving issue until the OP swaps to 4.56 or 4.88 gears.
 
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