Any real world experience with 4:88 gears?

[TheNewWampsCat]

So I’ve been debating something with gearing. I’m an old guy that does have a desire to jump to 37” tires. I’m running 315/75/17. They are actually 33.5” tall. I’ve been thinking of a gear change to gain a little bit of power back, if you look at the charts around 4:56 is close to where the factory was. But why not go to 4:88s? Then I read about 5:13s. I’m still wanting to run down the road at 70 or so and not kill my MPGs. I also tow the boat(3500#), smaller tractor(4500#), and a camper(4500#). So my question is which gear ratio makes the most since?

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[DankjeeP]

4.56 is probably right up you alley. Sounds like a little more grunt is going help. 4.88 is probably little too deep, unless you go to 37's.

 

[Gvsukids]

So I’ve been debating something with gearing. I’m an old guy that does have a desire to jump to 37” tires. I’m running 315/75/17. They are actually 33.5” tall. I’ve been thinking of a gear change to gain a little bit of power back, if you look at the charts around 4:56 is close to where the factory was. But why not go to 4:88s? Then I read about 5:13s. I’m still wanting to run down the road at 70 or so and not kill my MPGs. I also tow the boat(3500#), smaller tractor(4500#), and a camper(4500#). So my question is which gear ratio makes the most since?

What current gears do you have?

 

[hjdca]

I have 5:13s and 37s and a stick shift. With 5:13s and 37s, you have to go approx 95 to 100 mph to get to 3K rpm in overdrive. I have never quite got there.... The acceleration and additional power from stoplight to stoplight with the 5:13s is impressive. Changing to 5:13s is on of the best things I did to my truck. 4:88s are also good, but, if you are towing, you should consider 5:13s. I would not get anything less than 4:88s. You need the acceleration and torque multiplication of the higher gears.

 

[spectre6000]

Save that he explicitly stated he wants nothing to do with 37s, and almost certainly has an automatic...

Depends what you want: MPG, factory, or grunt. Each has its benefits and its costs. If you liked how it felt stock (maximize mpg and power without being really great at either), retain the most numerically similar ratio you can get. If you felt like it was a big of a dog stock, going one more up the ladder might cure what ails you (more power at the expense of mpg, assuming normal behavior... it can be gamed to get good mpg). Higher gearing, if you can keep your foot out of it, can net you higher mpg. Towing won't be great, and you'll be the last out of the light, but low-mid 20s mpg is achievable.

If you have a Mojave/Rubicon/Max Tow, you're currently running at a pretty much stock Rubicon setup, and that should get you factory level performance. If you have the 3.73 from any other trim, and are OK being the last out of stoplights, etc. Give it some time and drive pretty conservatively, and you might see some good fuel economy numbers. If it's borderline, step up one. If it's obnoxious, two. 5.17 would be completely ridiculous in your case, and you're pretty much guaranteed to rue and lament it.

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