... There is a whole lot of off base information in this thread.

think of it simply like this. Your gears are additional muscle that you're adding to your drive-train to help move all the additional mass you have added to your Jeep; ie, Larger tires and heavier wheels, bumpers, winches, aftermarket sport cages, tools, people and the list goes on. Re-gearing to a lower, or for these purposes "stronger" gear ratio will allow you to move all that extra weight much easier. Conversely you will have to use more energy to move much faster, say 85 mph or more, but that's the trade off and you said you were okay with that from the outset.

Honestly, other than perhaps cost, there is NO disadvantage to re-gearing. In other words, if you have everything to gain and nothing to lose by going this rout.

and for what it's worth, 4.56's are a waste of time. Some people say their great, but the difference between 4.56 and 4.88 isn't that much and it will be better to have that power than to not and wish you did. My .02

 

I though I understood gearing until I read this thread. I assumed the sweet spot was the cells on the gear chart shaded in green. For 35s, it shows 5.13s and 5.38s. Am I not reading the chart correctly? Is the tire size manufacturer spec or actual height under load? What is all this talk about anything less than 5.13s for 35s?

For what it's worth, I went with 5.38s to push 325/60s (measure 35 1/4 under load) on a 2010 jku auto. Also have a Ripp Gen2. RPMs at 70 are exactly what the chart says. It drives great on and off road.

Most of the fellas I ride with have gone with 5.13s and feel it was the best mod they did, other than 35s!

Please educate me.

 

Most of the thread is about a manual trans. The gearing in the transmission is different than auto so the diff sweet spot gearing is different.

 

So I haven't regeared, stay out of OD, it always stays in 3rd, and my highway mileage is in the 19's. Same tire by the way, but on a 16" wheel. You must be driving 80mph or more?

 

I said there are pros and cons. That means in some way NOT regearing is BETTER. And in some ways, it is other way around. Which part of it is hard to understand?

 

I am broke... so $1,000 for gears may as well be $1,000,000. However- I would be retarded to try to make a few HP with $200 here and there. If I want PERFORMANCE, I have to save up for gears. If I want HORSEPOWER, I'll save $5,000 up for a turbo.

 

Not true, with 4.88 gears your acceleration in any gear will beat stock 3.73 much less 3.21. Reason being is that it is easier for the engine to reach peak hp. The only true advantage of higher (numerically lower) gears have as far as speed is a higher top speed assuming the engine/ aerodynamics even have the potential to reach a theoretical top speed.

This^^
Also don't forget autos have torque converters so in no way can you compare autos to sticks in terms of tranny gearing, its like apples and oranges.

 

I was specifically talking about tires upto 35", as I don't have experience with larger tires. With larger tires 1st gear may suffer enough to justify a regear, or it may not. If 1st gear is still acceptable, then you can ride on stock gears.

 

Here's a quiz: In which ways can one achieve higher rpm at 85mph?

Well, cost is a big one. No need to try and slide it under the table. Another disadvantage you are weakening your pinion gear. Of course, if you only drive on road, then that isn't an issue. If highway driving is really important, then keeping stock gears would allow you to downshift to get a few more rpm's without reving excecivelly high. This is especially true on an auto. 6 speed manual is more forgiving though. For example, if I regear to 5.13 (auto), then I have weakened my diff gears, plus my rpm's will go down on the highway, which I don't want. And if that's not enough, I'll end up much poorer too. I will definitely lose in 3 major areas.

 

And that same RPM that you see in the green box, can be achieved in what other ways?

The actual tire height that you set on your Superchips or Procal should be used in the chart.