MPG change with new gears?

Gren71

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Im jusr curious, since im almost out of warranty, has anyone seen any increase in MPG with better gearing? ive been eyeing 4.88 or 5.13 rear gear just for towing but dont really know enough to make an informed decision. I have 285/75/17 tires and also dont intend to go larger. Ive read a couple threads where guys have changed to a 5.13 and were absolutely pleased with the better response.





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WK2JT

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If my metric to imperial conversion skills worked correctly, that’s about a 34” tire. Plus you are in a lower elevation so no concerns with power loss like CO. I think you would be better served with the 4.88. I’m on 37’s and moving to CO, so I’m going with 5.13. With 5.13’s and 37’s, my calculated 80 MPH RPM is 2,600. That’s about the upper limit I’m comfortable with... others may and probably do have different options. In the end, there is only about a 5% difference between the two ratios. It sounds like those with 4.88 and 5.13 are happy.
 

bastage

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With that small of tire then 4.88's should be more then enough.
 
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Gren71

Gren71

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With that small of tire then 4.88's should be more then enough.
but are they worth it? Like i said I dont really know enough to make en informed choice. Im starting down the path of learning but wanted to see if there was a measurable benefit to the upgrade if its just a daily driver and towing machine for me.
 

WK2JT

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but are they worth it? Like i said I dont really know enough to make en informed choice. Im starting down the path of learning but wanted to see if there was a measurable benefit to the upgrade if its just a daily driver and towing machine for me.
I think so, especially for towing. Even more if you’re on 3.73’s now. Even stock Rubi owners have upgraded to 4.88’s and liked the results. I personally don’t drive this thing over 70 MPH much, so I definitely want the deeper gears for drivability and towing. I rarely see 8th and 7th peeks it’s head up just slightly more, so I *think* it is definitely worth it. I would have already pulled the trigger if I wasn’t moving, but want to be close to the shop that does it in case there are issues.
 

wvyankee2

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I'm running 285/75/18's (35/11.5/18) 66 pounds per tire. Put in 488 gears. I'm getting 17MPG everyday driving which for me is about 75% Interstate @ 75MPH. Stock Overland I got 20.5mpg same driving. I'm in 8th gear nearly all the time in Western side of West Virginia. Small hills around here.
 
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Gren71

Gren71

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well that is encouraging for sure. I see 8th pretty much all the time and currently get 19-21mpg for highway and 17-19 local. I have 4.10's in my max tow
 

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