Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 20 of 24 Posts

Registered
Joined
44 Posts
Discussion Starter · #1 ·
I just ordered some 315-70R17 Nitto Trail Grapplers for my '14 JK. It's a 6 speed & currently has 3.73 gears. I plan on regearing it eventually but I don't know if I should go with 4.56 or 4.88 gears. 70% of my driving is street at 40mph or less, 20% at 55-65mph & 10% on easy to moderate trails. Just looking for advice on which one to go with. I dont plan on ever getting tires bigger than 35's. Thanks for any advice...
 

Registered
Joined
1,648 Posts
[EDIT - It appears a few folks have found this post helpful, so I've added towing, which one of the thread posters reminded me about]

You'll get lots of opinions on this, but no definitive answers (though some will claim their opinions are that, and will likely post a pretty chart as evidence :lmao:). As someone considering the same choice, I'll give you my $.02:

4.56's are likely the right answer for 90% of folks running "35's". Reasons the other 10% would choose 4.88's would be:

1) Vehicle weight - A heavy 4-door could use the shorter gear. This probably doesn't apply to you, unless you've gone crazy with a bunch look-tough armor.

2) Tire size - When most folks on this forum say "35's", they really mean 315/70's, which are smaller than an LT 35. It only makes .25" to .5" of difference in weighted rolling diameter (generally 33.5" vs 33.75"), but that little bit of extra lever might push a 35 owner to the shorter ratio. This doesn't seem to apply to you.

3) Rural highway driving is a rarity - If you never have occasion to cruise for hours at 75+ mph, you may choose the additional responsiveness of a shorter gear over the slightly more relaxed cruising of a taller one. Based on what you posted, this might apply to you.

4) Altitude - If you live above 5000', you're significantly down on power compared to the same vehicle at sea level, and likely have long grades to even higher elevations. Shorter gearing, while it doesn't restore any power, can improve drivability at altitude. You didn't say where you live, so I don't know if this applies to you.

5) Wheeling - If you like to wheel hard trails - rock crawling, if you prefer - sometimes it's nice to have a really low gear. This doesn't appear to apply to you.

6) Towing - These things aren't great tow rigs, and the short wheelbase of the 2-doors makes them positively awful, but a shorter gear does help with towing drivability. This doesn't appear to apply to you.

No one single factor is likely to push you one way, or another, but if you evaluate your choices in light of all six factors, you'll make the right choice for you.

Mark
 

Registered
Joined
1,846 Posts
Really good info @ScaldedDog. I dont think i have seen a good breakdown like that.

FWIW i am going 4.88s because: 4 door, auto trans, 35 bfg km2, and all my wheeling is done at higher elevations.
 

Premium Member
Joined
878 Posts
If it were me I would go with 4.56 gears and I've got 4.88s in my 3.8L today. With the new engine I believe 4.56s would be very good with 35s and a 2012+ JKU. Considerations would include how high is the elevation where you wheel, how hard do you wheel, and do you ever see yourself going larger than 35s?
 

Registered
Joined
1,486 Posts
Another consideration is whether you tow a lot or do a lot of driving on the interstate.
 

Registered
Joined
44 Posts
Discussion Starter · #8 ·
Thanks for all the good input guys. Based on the comments here it sounds like 4.56 would be the best option for my needs ... mostly city driving with occasional highways & trails, no freeways or towing. Does anyone who went with 4.56 wish they would've went with 4.88?
 

Registered
Joined
1,648 Posts
Really good info @ScaldedDog. I dont think i have seen a good breakdown like that.

FWIW i am going 4.88s because: 4 door, auto trans, 35 bfg km2, and all my wheeling is done at higher elevations.
Thanks man. I've thought about this a lot, and will likely make the same choice you are, and for mostly the same reasons. Assuming, if course, that I can convince myself that my current 4.10/35 setup, which I don't like, is a $2000 problem.

Mark

Sent from my SM-G935V using Tapatalk
 

Registered
Joined
1,846 Posts
Thanks man. I've thought about this a lot, and will likely make the same choice you are, and for mostly the same reasons. Assuming, if course, that I can convince myself that my current 4.10/35 setup, which I don't like, is a $2000 problem.

Mark

Sent from my SM-G935V using Tapatalk


I feel you on the 4.10s. My having 3.73s are making the choice a whole lot easier. Don't know your area but 4wp has a special for 1300 bucks right now in my area.


Sent from my iPhone using Tapatalk
 

Registered
Joined
2,187 Posts
Thanks for all the good input guys. Based on the comments here it sounds like 4.56 would be the best option for my needs ... mostly city driving with occasional highways & trails, no freeways or towing. Does anyone who went with 4.56 wish they would've went with 4.88?

i can tell you that with my 37's and 4.88's, i wish i went with 5.13's, but the 4.88's are not that bad for me. with 35's, i would definitely go 4.88.
 

Registered
Joined
432 Posts
15 JK Rubi 6mt heavy armor on Nitto 35s. 4.10s were not going to cut it out in CO. I chose 4.88s. @ 65 I turn about 250o rpm. MPG is back to about 17-19 on the highway.

If the poster dosent live and wheel at elevation then the 4.56s would probably be a good choice.
 

Registered
Joined
623 Posts
Just went from 3.73 to 4.56 myself on 315s. 4.56 is perfect for the daily highway driver.

4.88 could be useful if you crawl a ton/tow/ live at altitude, but in my opinion the rpm mappings for 4.56 are better than those of 4.88 for long highway drives.
 

Registered
Joined
44 Posts
Discussion Starter · #14 ·
Just went from 3.73 to 4.56 myself on 315s. 4.56 is perfect for the daily highway driver.

4.88 could be useful if you crawl a ton/tow/ live at altitude, but in my opinion the rpm mappings for 4.56 are better than those of 4.88 for long highway drives.

Thanks. I was actually wondering which gear ratio would put the engine in a better rpm range on the highway. My concern is that the Nitto tires I bought are considered heavy compared to other tires of the same size. I just thought maybe 4.88 would turn them a little easier.

Is there really that much of a difference between 4.56 & 4.88 anyways that the average person would notice? Anyone driven both, with everything else being equal, that you could comment on the difference in drivability?
 

Registered
Joined
953 Posts
yes ,you will feel a seat in the pants difference with 4.56 vs 4.88 vs 5.13. 5.13 will be super aggressive... 4.88 will be slightly aggressive but nice... 4.56 will feel nice and would be a smart choice for a daily driver that only goes on mild to moderate trails.
 

Registered
Joined
2,187 Posts
if 4.56 with 35's feel like 4.88's with 37's, then it will still feel less responsive than stock. if you want a little more pep with 35's, go with 4.88. you shouldn't really notice the extra 200 rpms with the 4.88 in everyday driving, but i think you would miss the extra power if you went with 4.56. since you are not doing alot of highway driving anyways, the added pep of the 4.88 will be nicer in the city and rural roads where your going up hills.

just for reference, i hardly ever use 6th gear at 55-60, even with 4.88's.
 

Premium Member
Joined
1,729 Posts
Thanks. I was actually wondering which gear ratio would put the engine in a better rpm range on the highway. My concern is that the Nitto tires I bought are considered heavy compared to other tires of the same size. I just thought maybe 4.88 would turn them a little easier.

Is there really that much of a difference between 4.56 & 4.88 anyways that the average person would notice? Anyone driven both, with everything else being equal, that you could comment on the difference in drivability?
From everything I have read, 4.88 may be the better option for you for a manual trans, 35 KM2's and 4 door. I am getting 4.56 installed for my auto 4 door with 37 KO2's only because I see a turbo in my future.
 

Registered
Joined
249 Posts
Had same dilemma. Agonized over it. At the advice of 4WP and some others on the forum I went 4.88 (BFG MT, 2 door with 700lbs of bumpers and accessories). My concern was that I'd lose 1st and might have issues with highway driving. Neither have been a problem. 2800 rpm at 70. I'm not in the ECO range but not bothered by it. Recently took a short trip up the mountain and improvement was day and night over the factory 4.10s. Haven't wheeled it since the regear but expect I'll be very happy. I do prefer aggressive but not extreme wheeling. I'm content that I made the right choice. Based on what you've stated your driving habits are, I would say the 4.56 advice is sound but dont think you would be tererribly disappointed or feel you made a major mistake if you went 4.88.

Sent from my SM-T713 using Tapatalk
 

Premium Member
Joined
9,592 Posts
Based on your stated use, 4.88 all the way. I just finished a 5700 mile trip that saw every type of driving you can imagine. The only time 4.56 would be preferable is on the freeway at speeds over 70 mph and even at 80 mph my fuel economy did not suffer. 65 mph is really good with 4.88's. If you lived at altitude, say 5000 ft and up I would recommend 5.13's.

As a reference point with 4.10's and 35's my long term mpg 15.4, with 4.88's it's 15.7 and climbing and I do run the speed limit what ever it is.
 

Registered
Joined
44 Posts
Discussion Starter · #20 ·
Thanks again everyone. Still waiting for my tires and wheels to arrive. I'm curious to see how it will be running my stock 3.73 gears.
 
1 - 20 of 24 Posts
Top