tire weight with 321 gear ratio?

[patsfan]

Hi I have a 2013 jku, with an automatic transmission, 321 gear ratio, steel bumpers and winch, gobi roof rack, and 33 inch tires. My rig is a daily driver, in the three years I've had it I've only had it off road about a dozen or so times.

Recently added in a aev two and a half inch lift and Teraflex big rotor kit. I will be purchasing a new set of 35 inch tires in the next day or two, I have it narrowed down to the BFGoodrich ko2 35 12.5 17 or the Goodyear Wrangler DuraTrac 315 70 17, the BFGoodrich weighs 68 pounds the goodyear weighs 60 pounds.

My question is do you guys think the 8 pounds per tire is going to make 321 gear ratio even worse?.
$2,500 for a gear swap is not in the plans now or in the near future. Any advice would be greatly appreciated.

 

[JIMBO]

:sombrero: The 8 lbs has NO EFFECT on the 3.21/auto ops--(well-non-laboratory)

The 35" tire is too much rolling diameter load on the tranny--

You are adding looks and causing excessive jeep/driver suffering--

It's your jeep so you can do what you want, but the re-gearing is the primary mod, before use of 35" tires, actually even 33" tires aren't compatible with 3.21 gears and auto-

Re-gear first then 33/34/35/37 tires--the board is clear

Good luck

:costumed-smiley-007:wings: JIMBO

 

[jeep-N-montero]

Hi I have a 2013 jku, with an automatic transmission, 321 gear ratio, steel bumpers and winch, gobi roof rack, and 33 inch tires. My rig is a daily driver, in the three years I've had it I've only had it off road about a dozen or so times.

Recently added in a aev two and a half inch lift and Teraflex big rotor kit. I will be purchasing a new set of 35 inch tires in the next day or two, I have it narrowed down to the BFGoodrich ko2 35 12.5 17 or the Goodyear Wrangler DuraTrac 315 70 17, the BFGoodrich weighs 68 pounds the goodyear weighs 60 pounds.

My question is do you guys think the 8 pounds per tire is going to make 321 gear ratio even worse?.
$2,500 for a gear swap is not in the plans now or in the near future. Any advice would be greatly appreciated.

So you have money to blow on new tires but you don't think you should spend it on new gears instead? I would be hating life even with just the 33's and crappy gearing. Here is another idea, sell it and buy a Subaru.

 

[Septu]

I agree with Jimbo. If you had a 6 speed, you might be able to tolerate it. But with the automatic I think you're going to be fairly disappointed with how it drives with 3.21 gears after putting 35s on it. I haven't had 35s on the 3.6l but I had 33s on my 07 6spd with 3.21s, and it was very noticeable. Fortunately that was a stick and I could just rev it a little higher if needed and shift manually. Read up on it - but I suspect that most who've attempted this re-geared down the road.

 

[rubicon91]

Oh man I will tell you it will suck if you do go to 35s. I have a 12 manual. Had 321 gears with 33s. Was ok due to the manual trans but I could never use 6th gear. So right before I got 35s I regeared to 456s. Let me just say this. Why did I not do this before. Hands down the greatest addition to my Jeep was regearing. Now $2500 seems way tooo steep. I would check around. $1500 here is the going price approx. I would never think about 35s and 321 with the manual much less an auto with a gobi rack winch bumpers etc. I just cannot see how it would be enjoyable to drive for any period of time.

 

[MTSN]

I would do the gears first then the tires later especially considering it's a daily driver. I've driven under-geared Jeeps before (basically all of college actually), and life is so much better when you're geared correctly.

 

[sgregg108]

I'm driving a 2013 JKU with 3.21 gears / automatic, 17" wheels and 315x70 BFG KOs calibrated accordingly with the AEV pro cal. The Jeep is loaded with a steel stubby front bumper, dom tube rock sliders, superwinch talon 9.5 w/steel cable and a Metalcloak full-width rear bumper / tire carrier. It's my daily driver and it's honestly not that bad. Even when I took her to death valley and brought a 5gal jerry can and had 3 days worth of camping stuff loaded into her, it did well. When I'm on steep grades on the highway it does get into the 3,500 - 4,000 rpm range but it's not bad and the temp gauge barely moves. I get around 15-17 mpg, I think you're fine with it as is.

 

[jeep-N-montero]

Hi I have a 2013 jku, with an automatic transmission, 321 gear ratio, steel bumpers and winch, gobi roof rack, and 33 inch tires. My rig is a daily driver, in the three years I've had it I've only had it off road about a dozen or so times.

Recently added in a aev two and a half inch lift and Teraflex big rotor kit. I will be purchasing a new set of 35 inch tires in the next day or two, I have it narrowed down to the BFGoodrich ko2 35 12.5 17 or the Goodyear Wrangler DuraTrac 315 70 17, the BFGoodrich weighs 68 pounds the goodyear weighs 60 pounds.

My question is do you guys think the 8 pounds per tire is going to make 321 gear ratio even worse?.
$2,500 for a gear swap is not in the plans now or in the near future. Any advice would be greatly appreciated.

And after reading your thread on coming out to Moab then re-gearing is even more crucial.

 

[patsfan]

I really don't see the need to be rude guys.

No I don't like Subarus so I will not be buying one.

So the comment about spending money on new tires and not on the gearing might be a valid one, except that my 33 inch duratracs are very worn and to the point where they're almost not safe anymore so I need new tires anyway so I figured might as well.

I live in Rhode Island and I've called around to several shops and they're all around $2,500 or more for gears and labor.

By the way 33 inch tires and 321 gear ratio has been fine with the way I Drive, remember its a daily driver and I don't go off road all that often.

So we all know that regearing with 35's would be the best situation there's no dispute, but after a lift, new brakes, Wheels & Tires, oh and don't forget a tire carrier a $2,500 mod is not in the cards, I'm sure that a realistic person could understand that.

So back to my original question does anyone think that the 8 extra pounds will have an effect?

By the way thanks to the couple of people who responded with actual advice.

Edit: after reading through all the responses again it really was only jeep n Montero who was rude, thanks for the rest of the replies

 

[JeepinMike]

It's not so much the 8 extra pounds that you have to worry about it has more to do with the rolling resistance of a 35in tire. If you really want 35s go for it just know that you'll likely need to regear shortly after.


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[Dan Grec]

If you never offroad it, why are you going with 35s?

It will drive way nicer with 33s, and you'll get better mileage to boot!

-Dan

 

[Septu]

If you never offroad it, why are you going with 35s?

It will drive way nicer with 33s, and you'll get better mileage to boot!

-Dan

Hard to fault him... a JKU honestly does look better with 35s. 33s are a lot more practical but the 35s just fill it out better. And before anyone says that it shouldn't matter... suck it. I'm vain and like my **** to look good.

 

[Happy Joe]

As Jimbo said the 8 pounds per tire will have negligible affect. As far as gear ratio (tire diameter) will have an affect on drivability and gear ratio, as many have said.
Additional tire/wheel weight will result in somewhat increased stopping distance.
Probably the only reason that you are somewhat happy with 33s and 3.21s is the automatic transmission; manuals are much more sensitive to tire size changes as far as drivability is concerned.
Post back and let us know how you like/dislike the drivability after the change...

Enjoy!

 

[patsfan]

If you never offroad it, why are you going with 35s?

It will drive way nicer with 33s, and you'll get better mileage to boot!

-Dan

That was my plan but after I installed the 2 1/2 inch AEV lift my 33 inch tires just look too small

I only installed the lift because after 65000 miles the Jeep started to ride like crap, so instead of replacing it with stock parts I figured why not upgrade to a better riding suspension, my brakes were also worn so again instead of stock I upgraded to the Teraflex big rotor kit.

 

[Kmrtnsn]

I have a '13 JKUS myself, rolling 33" tires, a 2.5" lift, and I am going to re-gear to 4.56 before moving one size to 34" tires. My advice, spend a grand and re-gear first.