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35's with 3.21 Gears

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Old 01-25-2011, 06:41 AM
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Originally Posted by Rusman161
Dealership can only set your tires to a 265 size, I just had a run in with them about it.

I live in the Houston area, just about everything is flat and I'm running 32s. I'm only getting 14-15 mpg period. The best mpg ive ever gotten from mine is 20.7 and that was on a 14 hour drive! I'm not heavy on the pedal, just all the damn traffic and overpasses.

I'm goin' with 35s as soon as these duratracs wear out, but I'm dreading it because my jeep will be even more sluggish and worse on mpgs. I am considering regearing before the 35s, I'm hoping it will make the jeep feel less sluggish.
I regeared before going larger than 265's. Best thing I've done to the Jeep.
Old 01-25-2011, 08:09 AM
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Originally Posted by tslewisz
AEV ProCal, not "pro comp".
#

Yeah ProCal that's it two out of three isn't to bad for me
Old 01-25-2011, 08:46 AM
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20+ MPGS?! that unheard of in my parts. even when i was stock. best i got was 19 mpg and thats from the jeep's computer. i averaged 17-18 with my stock setup, and now i'm averaging about 14. details in sig. regearing will come eventually, but honestly, its not bad. i drive a 4-door 6 speed, and i live in seattle. lots of hills here. dont use 6th all that much, so 5th and i got friendly. still have to get a programmer. cheapest i've seen was 149 or something for just the speedo one. i plan to get a hypertech or something to try and increase performance, but even if it does, it'll be minimal gains.
Old 01-25-2011, 09:21 AM
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Originally Posted by Rusman161
Oh I forgot to add:
If you get an aftermarket device and you want to keep what warranty you have left (if you have one) the programmer can only
Change tire size. The jeep will tattle to Chrysler the next time you bring it in and then they bust out their big ol' VOID stamp to slather all over your warraty.
Even if you reflash it back with the stock tune before carrying it in? I did not think that was the case.
Old 01-25-2011, 09:35 AM
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Originally Posted by tpm152

Did you recalibrate your computer to account for larger tires? If not that could account for some of the loss in MPG.
Recalibrating his computers will not give him any back in mpg, unless you going of the hugely inaccurate computer mpg read out! He is running a manual tranny, so shift points will not change. 14-15 mpg is what I get with 35's there isn't much you can do about that. Just remember bigger tires more distance covered so if your speedo says 60 when you are still programed with smaller tires your probably going 66-68 mph. That will give you some mpg's back if that's the way your thinking about it?
Old 01-25-2011, 10:01 AM
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Originally Posted by crazyloggy
Recalibrating his computers will not give him any back in mpg, unless you going of the hugely inaccurate computer mpg read out! He is running a manual tranny, so shift points will not change. 14-15 mpg is what I get with 35's there isn't much you can do about that. Just remember bigger tires more distance covered so if your speedo says 60 when you are still programed with smaller tires your probably going 66-68 mph. That will give you some mpg's back if that's the way your thinking about it?
If you don't correct the tire size then the odometer is off so mileage can't be computed accurately. The best you can hope for is to use a GPS to check how far the odometer is off and compute using mileage times a percentage. And that is still not going to be as accurate.
Old 01-25-2011, 10:10 AM
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Wow, I have never heard of 20+ mpg either. You were really taking it easy. I am at 16 stock.
Old 01-25-2011, 10:24 AM
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Originally Posted by 4fit?

Even if you reflash it back with the stock tune before carrying it in? I did not think that was the case.
I do not know if reflashig works, but the jeep computers, much like any vehicles computer these days has a tattle tale system build in. Perhaps reflashing would
Solve it before taking it in.
Old 01-25-2011, 10:27 AM
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Originally Posted by mediocre69

If you don't correct the tire size then the odometer is off so mileage can't be computed accurately. The best you can hope for is to use a GPS to check how far the odometer is off and compute using mileage times a percentage. And that is still not going to be as accurate.
Changing the tire size does correct the odometer and mpg calc, but most importantly it changes when your transmission shifts. This results in more efficient driving and boosted mpgs, plus less wear for being in the wrong gear
Old 01-25-2011, 10:42 AM
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265's???? I thought that number pertained to the tire width? ??


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