Hello everyone! I have another question to ask the forum regarding the 4:10 vs the 3:21 ratio. How much difference would you see between the two and what are the positives/negatives between them? At which point would I be sorry I went with the 3:21 instead of the 4:10? My Sahara is still on order with the 3:21 and currently in D1 status. If the 4:10 is going to be that much better, I want to change it before it is too late.

This forum has been the most infomative place for me to find good information regarding questions on my JK so thank you in advance to all that reply.

 

since it's only a $50 extra option, i would recommend getting it. I know i'm glad that i did... you can feel the difference

 

Firstly, I am no expert but I have the 3:21's and after reading this forum it really depends on what you want it for.

Towing is the main thing I think, I can only tow 1000lbs. and 4:10 can tow 3500lbs.

3.21 is better for highway driving for gas mileage. 4.10 gives you better lower end.

If you plan on going bigger tires get the 4.10, I would have but they had exactly what I wanted on the lot the 1st day I looked but had 3.21's, will upgrade at a later date when money becomes available. I am happy with it now, but will upgrade later.

Someone can correct me if i'm wrong.

 

Fraynes has a point. It all depends on what you'll be using your jeep for. If it's just highway and normal road driving, even light trailing, 3.21 will do just fine, and better gas millage. But if you're planning to put 33" or 35" in the future, get 4.10 (unless you're planning to put 4.88 or 5.13 in the future, then don't bother getting 4.10).

I would rather wait a bit and find 4.10 (only $50 extra) than spending a lot of money and re-gearing 3.21 to 4.10...just my 2 cents

 

You're not wrong, but there are a few points you missed.

First, I think we can assume that Jeeperson isn't going to be towing, since the towing package would've bumped up the gear ratio to 4.10. But, towing isn't the only consideration.

If you ever intend to put a lift and/or bigger tires on your Jeep, get the 4.10 from the start. Even then, going to a 35" tire would probably warrant a regearing down the road, but the 3.21 would be PATHETIC with a lift and bigger tires...

Next, if you're going to be wheeling, get the 4.10 - no contest - you want to put down as much torque as possible on the wheels, and the 4.10 wins that contest, hands down.

Finally, gas mileage really shouldn't be a consideration, because it's a Jeep. You're going to get crummy gas mileage with the 4.10, and MAY gain 1 mpg with the 3.21, if you baby the throttle... but when you want to GO, you're going to be wishing you had gotten the 4.10.

Honestly, I don't have any idea why the 3.21 is offered at all; the only "advantage" I can see is slightly increased (yet still piss-poor) gas mileage. Get the 4.10 now, or wish that you did.

 

tire size and gearing work together. if you have shallow gears, and big tires, you are going to bog down the engine, making it work harder and expend more fuel. by the same token, if you are running pizza cutters with 5.13's, your rpm's will be off the map, also using up more fuel.
i'd say with anything larger than a 28" tire, go with 4.10.