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I did upgrade from 321 to 373 gears. Through Jeep dealer it was only $600 upgrade on a new JKu 2017.

I knew I was not going bigger than 35 inches. I went 305/70r17 which is about 33.8x12.2 on a 17x9 rim lol.

It is expensive to re gear after market. Like $2000. Why bother?

It seems fine on my JKu. I get on highway just fine. My JK is tuned for it and the automatic downshift Is fine for braking.

Sometimes I floor it.

Sometimes you can just put these new automatic transmissions in manual shifting mode and shift from 1st to 6th gear if you want. Or 6th to 1st.



Sometimes an easy tap on the gear handle in drive to the left to downshift or a tap to the right to upshift.

Smoother and responsive.
 

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You only have 5 gears unless you are counting reverse
 

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Because living in FL you do not have the hills and mountains like some of us do. Plus towing at near max capacity on those hills and mountains. For you regearing is not a big deal, but for me (even when I had 285s) regrearing was almost paramount.
 

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You can ask your auto transmission to shift gears all you want. It will never have as much acceleration, pulling power, or ability to crawl, as a JKU with that size tires and a better gear ratio (like 4.10 or 4.56). Perhaps you don't need that acceleration, pulling power, or ability to crawl. But to me the 3.73 gears are really to tall even for the 265/70-17" that our JKU came with. I will probably wait until I get bigger tires to re-gear, only because I only want to re-gear once (I hope). But in my opinion it really needs at least 4.10's with that size tire, 33's would only be worse.
To each their own.
 

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Because living in FL you do not have the hills and mountains like some of us do. Plus towing at near max capacity on those hills and mountains. For you regearing is not a big deal, but for me (even when I had 285s) regrearing was almost paramount.
Re gearing voids the warranty unless done buy Jeep?

So instead of gears, what about a power tune and/or Air Intake mod. You can get 30HP to 50HP extra for 10% to 20% increase in engine power.

I would think most already own a tuner and just need to maybe upgrade it for $250. You can run 93 octane for power or change the tune to stock for 87 octane and save money.

Big fan of tuning JK for tires. Forget about shifting up. If affects deceleration and stopping distance alot with hitting down.
 

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The jeep engineers designed the tire size, axle gear ratio, and transmission together to work with in the motors optimal power/torque range for best performance and gas efficiency. Changing the tire size changes that equation. Reprogramming the shift points can help a lot, but changing gear ratio can bring it all back to the design engineers specifications. Your *cough*cough* "30HP to 50HP extra for 10% to 20% increase in engine power." helps compensate, but not correct the change. Like me, most will gear even lower than needed to further help performance. There are plenty of threads here on the benefits of a regear. However,if you happy with your jeeps performance, save the money and don't regear.
 

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Re gearing voids the warranty unless done buy Jeep?

So instead of gears, what about a power tune and/or Air Intake mod. You can get 30HP to 50HP extra for 10% to 20% increase in engine power.

I would think most already own a tuner and just need to maybe upgrade it for $250. You can run 93 octane for power or change the tune to stock for 87 octane and save money.

Big fan of tuning JK for tires. Forget about shifting up. If affects deceleration and stopping distance alot with hitting down.
Tuning also voids the warranty. And with this engine you can't get 30-50hp with tuning and intake mods. You might get 15-20 from tuning and that will be in an rpm range you don't see every day, intake will do nothing.
 

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Add 25 cents to that dollar. I would like to see that too. What are you thoughts on deer whistles
 

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I did upgrade from 321 to 373 gears. Through Jeep dealer it was only $600 upgrade on a new JKu 2017.

I knew I was not going bigger than 35 inches. I went 305/70r17 which is about 33.8x12.2 on a 17x9 rim lol.

It is expensive to re gear after market. Like $2000. Why bother?

It seems fine on my JKu. I get on highway just fine. My JK is tuned for it and the automatic downshift Is fine for braking.

Sometimes I floor it.

Sometimes you can just put these new automatic transmissions in manual shifting mode and shift from 1st to 6th gear if you want. Or 6th to 1st.



Sometimes an easy tap on the gear handle in drive to the left to downshift or a tap to the right to upshift.

Smoother and responsive.
Your size tire is similar in performance range (not counting for extra mass and diameter effect of the larger/heavier tire) to the 3.73 and 32's on a manual transmission according to the gear charts floating around out there, so very similar to a Sport with 17's or Sahara with 3.73's and manual transmission. Jump up to a 35 and you might start noticing it. I just went from 265/70/17 load C's (45lb duratrac) to 285/75r17 load C ridge grapplers @ about 65lbs each and the same 33.8 diameter on paper. It's not a lot but there is a definite difference on my 3.73's manual tranny.

edit: it will be interesting to see the effect this weekend when I take a road trip with hills. Already had to downshift to 5th and sometimes 4th to maintain 60-65 on the route I'm taking.
 

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Re gearing voids the warranty unless done buy Jeep?

So instead of gears, what about a power tune and/or Air Intake mod. You can get 30HP to 50HP extra for 10% to 20% increase in engine power.

I would think most already own a tuner and just need to maybe upgrade it for $250. You can run 93 octane for power or change the tune to stock for 87 octane and save money.

Big fan of tuning JK for tires. Forget about shifting up. If affects deceleration and stopping distance alot with hitting down.
Because tuning also voids warranties.

Also, Tuning on top of low gearing, big tires, and an automatic is just rubbing salt in the gunshot wound.

You are adding power on top of a less than optimal situation.

Yes the engine has more power and can make the pull, but the transmission has not been beefed up and is still the weak spot in this equation. Until you beef up the transmission, it's still going to have to work just as hard (if not harder) to get the heap moving.

It's easier to just do it the right way and regear.
 

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Re gearing voids the warranty unless done buy Jeep?

So instead of gears, what about a power tune and/or Air Intake mod. You can get 30HP to 50HP extra for 10% to 20% increase in engine power.

I would think most already own a tuner and just need to maybe upgrade it for $250. You can run 93 octane for power or change the tune to stock for 87 octane and save money.

Big fan of tuning JK for tires. Forget about shifting up. If affects deceleration and stopping distance alot with hitting down.
I hate to tell you but nearly everything you modify potentially voided some part of your warranty... just a fact of life
 

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A better question is with thr new 6 - 10 speed automatic transmissions, why don't the manufacturers do a better job of gearing for performance? At least with optional gear sets .
 

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I did upgrade from 321 to 373 gears. Through Jeep dealer it was only $600 upgrade on a new JKu 2017.

I knew I was not going bigger than 35 inches. I went 305/70r17 which is about 33.8x12.2 on a 17x9 rim lol.

It is expensive to re gear after market. Like $2000. Why bother?

It seems fine on my JKu. I get on highway just fine. My JK is tuned for it and the automatic downshift Is fine for braking.

Sometimes I floor it.

Sometimes you can just put these new automatic transmissions in manual shifting mode and shift from 1st to 6th gear if you want. Or 6th to 1st.



Sometimes an easy tap on the gear handle in drive to the left to downshift or a tap to the right to upshift.

Smoother and responsive.
No offense, but drive a Jeep that has been geared correctly. I've had/have 2 JKs with 3.73, stock tires up to 35s. And a Jeep with 4.10s stock tire to 37s. (Also 4.88 gears.)My wife's Jeep is 3.73 with 35s, it's OK most of the time, but gearing to 4.56 would be much better. I don't try to kid myself otherwise......

The choice is really simple, gear the Jeep correctly for optimal performance and add larger brakes to compensate for the larger tires.

As far as tunes and intakes, no thanks.
 

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Re gearing voids the warranty unless done buy Jeep?

So instead of gears, what about a power tune and/or Air Intake mod. You can get 30HP to 50HP extra for 10% to 20% increase in engine power.

I would think most already own a tuner and just need to maybe upgrade it for $250. You can run 93 octane for power or change the tune to stock for 87 octane and save money.

Big fan of tuning JK for tires. Forget about shifting up. If affects deceleration and stopping distance alot with hitting down.
Most cheap performance mods are a sham that do nothing for you other than take your money. Here are some comments from another Jeep forum site:

"Keep in mind, it is a V6 that is already outputting 270-280 bhp and 240-270 ft/lb of torque. Slapping an "axel back" muffler or a "high flow" air filter will do very little in terms of performance. To make more power on any naturally aspirated motor you have to think about the properties of the air flow, after all, your engine is just a really big air pump. If you change the air filter out to a less restrictive filter, but leave the restrictive air pipe in place, you may see minor differences due to air velocity, but you are not physically flowing any more air, and therefore cannot increase the amount of fuel without changing your air to fuel ratio. There is a whole heck of a lot more that goes into creating power, safely, and efficiently, than a $30 air filter and chip."

"I purchased a kit from Road Race Motorsports that includes intake, exhaust and chip for about a grand. It actually hurt power, and have heard others complain about the same. Then I bought the BullyDog performer to run my JK with 91 octane for more power. This also resulted in no gain at all.
At this point, I've come to realize that the Pentastar is giving about as much power is it can give right off the dealership.... aside from forced induction."

Information about any valid performance mods will include complete before and after dynamometer test data. Most fail to provide that in their advertisements. Most that do provide it are lying.

 

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Y'all are talking about acceleration and pulling trailers and what not.

Nobody seems to have brought up the fact that the gearing will also let you go SLOWER with far more control.

That's one of the big advantages the Rubicon has right off the showroom floor with it's 4:10's and different transfer case. At idle it will crawl slower and with more torque to get through obstacles well under control.

I saw a video here a while back demonstrating this behaviour and found it to be a revelation.

With the 3:73's and the non-rubi transfer case, your crawl speed is higher and when going through rocks or through a forest you may find yourself dragging the brakes to keep control. The bigger your tires, the bigger this issue will be as you'll go faster and faster at idle.
 
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