Went 4.56 but should I have gone with 4.10 gears?

Pullen724

New Member
Joined
Nov 19, 2019
Messages
3
Reaction score
2
Location
Conroe Texas
Vehicle(s)
2019 JLU Sport S
Ive got a 2019 JLU Sport 3.6 AT with 35” Ridge grapplers that measure right at 34” true height.

Recently regeared to 4.56 but my RPM’s are 350-400 RPM’s higher in 8th gear than the stock setup (stock tires and 3.45 gears).

Trying to see if I would be better off going down to 4.10 gears for better highway use and MPG. Would it make much difference on my RPM’s to go from 4.56 to 4.10? Would I lose 8th gear again?

This is an on road only vehicle.

Any long term issues running 350-400 RPM’s higher throughout various speeds compared to stock?

Here are my stock #’s as well as after regearing to 4.56

With stock tires and stock 3.45 gears:

50 - 1250 rpms
60 - 1500 rpms
70 - 1800 rpms
80 - 2100 rpms

After 2” mopar lift, “35”” Ridge Grapplers and 4.56 gears:

50- 1600 rpms
55- 1700 rpms
60- 1900 rpms
65- 2100 rpms
70- 2250 rpms
75- 2300 rpms
80- 2500 rpms

All speeds are MPH and in 8th gear.

Jeep has great acceleration, uses 8th gear consistently through all normal speeds and feels good with the 4.56 gears, just concerned about the higher RPM’s.

Thanks in advance for your thoughts
Advertisement

 

flot

Well-Known Member
Joined
Dec 17, 2018
Messages
163
Reaction score
199
Location
South Florida
Vehicle(s)
Waiting on a 392
I think you're fine, 2500 rpm is a reasonable operating range for the 3.6 and I'm assuming you aren't driving 80 mph all day long.

Your fuel economy will probably suffer a bit, but you'll spend more in re-gearing than you would save in fuel over 5 years so...
 

IceBerg

Well-Known Member
Joined
Oct 29, 2019
Messages
164
Reaction score
230
Location
Texas
Vehicle(s)
2018 JLUR
how much money do you want to spend now to save $500 in gas over the life time of the ownership of your jeep?

I'm about to put 4.56 gears in my jeep for 35s. If anything enjoy the extra pep/torque.
 

cb4017

Well-Known Member
First Name
Cliff
Joined
Jul 27, 2019
Messages
170
Reaction score
210
Location
Northern Nevada
Vehicle(s)
2021 Gladiator Sport
Occupation
Retired
You will not hurt anything running those RPM. If you like the way it drives then enjoy your Jeep.
 

rkj__

Well-Known Member
First Name
Ryan
Joined
Jul 11, 2019
Messages
252
Reaction score
286
Location
Ontario, Canada
Vehicle(s)
Sierra, Countryman, RZR
4.10 gears might have been better, but what's done is done. The RPMs you listed are still within a reasonable range IMO.
 

UKCATS

Well-Known Member
Joined
Aug 7, 2018
Messages
1,865
Reaction score
5,034
Location
DFW
Vehicle(s)
2020 JLUR Recon/2020 Mazda3 Hatchback
Occupation
I play piano in a whorehouse
I was running 4.88’s with 35’s and found it perfect for my tastes. As others have said, you are mine and made the right choice.
 

roaniecowpony

Well-Known Member
Joined
Dec 4, 2018
Messages
2,441
Reaction score
2,621
Location
90505
Vehicle(s)
2018 JLUR, 14 GMC 1500 CC All TERRAIN
Occupation
Retired Engineer
I sure wouldn't change gears for such a small difference. Next time you need tires, you could go up to 37s, but it will be a bit more sluggish.
 

entropy

Well-Known Member
Joined
Sep 19, 2018
Messages
2,711
Reaction score
4,110
Location
Pasadena
Vehicle(s)
Jeep Wrangler Sport S JL 2-D
Build Thread
Link
Occupation
Data Scientist
Take that poor Jeep to the beach at least. All this trouble just for the road? give it 1 day of freedom :flag:and stop worrying so much about +-1 MPG. If you worry so much about MPG why get a Jeep in the first place AND put 35s on it!
 

DanW

Well-Known Member
First Name
Dan
Joined
Mar 2, 2017
Messages
7,710
Reaction score
9,845
Location
Indiana
Vehicle(s)
18 JLUR, 08 JKUR, 15 Ford Transit 350, 04 WJ 4.7, 17 Renegade, 99 Merc E430 S
Vehicle Showcase
2
Ive got a 2019 JLU Sport 3.6 AT with 35” Ridge grapplers that measure right at 34” true height.

Recently regeared to 4.56 but my RPM’s are 350-400 RPM’s higher in 8th gear than the stock setup (stock tires and 3.45 gears).

Trying to see if I would be better off going down to 4.10 gears for better highway use and MPG. Would it make much difference on my RPM’s to go from 4.56 to 4.10? Would I lose 8th gear again?

This is an on road only vehicle.

Any long term issues running 350-400 RPM’s higher throughout various speeds compared to stock?

Here are my stock #’s as well as after regearing to 4.56

With stock tires and stock 3.45 gears:

50 - 1250 rpms
60 - 1500 rpms
70 - 1800 rpms
80 - 2100 rpms

After 2” mopar lift, “35”” Ridge Grapplers and 4.56 gears:

50- 1600 rpms
55- 1700 rpms
60- 1900 rpms
65- 2100 rpms
70- 2250 rpms
75- 2300 rpms
80- 2500 rpms

All speeds are MPH and in 8th gear.

Jeep has great acceleration, uses 8th gear consistently through all normal speeds and feels good with the 4.56 gears, just concerned about the higher RPM’s.

Thanks in advance for your thoughts
With 35's, you probably got it pretty close to where a Rubicon would have been with stock gearing, so you should be good to go. It would have been great with 4.10 gearing, too, but I think with 4.56, 8th gear will actually be where it should be, and it will now be more useful. I've got 4.10 gearing with 35's and the manual transmission and While I'm very happy with it, 6th gear is really only good above 60mph. It isn't bad, but I'd love to have 4.56 gearing to get shorten up both 5th and 6th a little. For me, anyway, yours is probably geared right at the sweet spot.

Don't worry about that 3.6. It loves to live at higher rpm, so I doubt that will actually result in less fuel economy because the engine won't be working hard, at all.
 
Last edited:

Jeep’n Jay

Well-Known Member
First Name
Jay
Joined
Aug 17, 2019
Messages
182
Reaction score
226
Location
Salt Lake City
Vehicle(s)
2018 JLU Sport
4.56 is only way to go for 35's, several have been unhappy with 4.10's and 35's
 

InvertedLogic

Well-Known Member
Joined
Aug 2, 2018
Messages
596
Reaction score
525
Location
Denver, CO
Vehicle(s)
19 JLUR
You're only 200rpm higher at 80mph than what a stock Rubicon sits at. I wouldn't sweat it. Enjoy the acceleration!
 

Bluebeast

Well-Known Member
First Name
Travis
Joined
Apr 21, 2019
Messages
189
Reaction score
107
Location
NorCal
Vehicle(s)
2018 JLU sport
If you don't mind me asking, about how did the regear set you back?
 
Advertisement

Freeland Jeep
 
Advertisement
Top