2025 JLU Sport drivability question....

[Matty_inkz]

What's up everyone. I read all the time, this is my 6th jeep. I have a 4 door Sport S 2.0T automatic with stock 3.45 gears, So far I've done blad mountain, peters mill, and every trail at Uhwarrie Nat Forrest. The mods I've done are....

-2.5 JKS lift with front and rear lower control arms as well as front and rear track bars and quick disconnects.

- I chose to put bilstein 5100 shocks and steering stabilizer in it instead of fox ( dont like fox )

-17 icon wheels with 33 toyo rt trails tires

-Rugged ridge mid stubby bumper

-Barricade 12,500lb winch

So it still has stock 3.45 gears and with out stubby bumper i was still hitting 22 to 24 mpg ( 415 a tank ) but with bumper and winch, now with them installed I get 15 to 16. So this Wednesday 12/10/2025 I take in to eastern 4x4 truck and accessories in Norfolk to get HD springs so it dosnt sag or ride low when loaded but also to handle the extra weight up front as it is noticeable driving that the nose weight is annoying hence the upgrade to HD springs front and rear. I also will do a reagear to 4.56 at this time as well.

My question is, will the HD springs and 4.56 get some of that fuel mileage back and hopefully stop the gear hunting on slight inclines and turns and be more nimble in general due to the new lack of aerodynamics and drag.

But what I have noticed till I do that this Wednesday, is that it just seems to get terrible gas mileage and feels like somthing is holding it back or causing resistance, I get and understand fully the drag and dynamics or lack of...BUT** it feels like it came out of no where, I cant see breaks or anything binding up, but I do notice that when in 4x4 high or low going over dips or mounds when the nose dips down ( on the decline not flying through or over them ) there is a metalic on metalic noise almost like abs or grinding coming through front cant really tell, but also when breaking hard on street I hear it as well, but never before have I heard it till recently. Also the gas mileage dropped to 280 miles per tank vs ( before bumper and winch ) was 390/415 miles per tank. Now I know from having jeeps before a JL this huge dip is not normal. I use premium 91/93 Oct every fill up and drive modestly, I dont speed and the fastest ill go is maybe 73 as virginia has low limits. It wheels just fine but I can't understand this drastic drop in mileage. Any help or input is appreciated. One way to uhwarrie it did 289 miles per tank but on way back was the same as well. The avg says 19.8 but mileage at fill up is 16.2 so im confused. Nothing is leaking or broken, but really feels like a dog now and when I give it gas it feels like I really have to lean I to the skinny pedal now to get it to move which it never did before. Like this came out of nowhere. The bumper and winch only added maybe 130lbs so imo not enough to crush the mileage this way. Just feels like brakes are always on even though they arnt and having to laying to the skinny pedal is annoying. Maybe im missing somthing. Any helps is welcomed and I thank you all

Again on Wednesday it gets HD Springs and 4.56 gears.

Sponsored

 

[Flip]

Welcome to the forum and congratulations on your new jeep. It's a beaut!

The last time I checked my mpg I believe I was getting around 22mpg but I haven't driven on the interstate in awhile so I'm sure that's gone down. I also run 33's aftermarket front & rear bumper and a winch but I have the 3.6 so not exactly apples to apples.

You say, you have to really lean on the gas pedal to get her moving. I'm wondering if there isn't something wrong with the turbo system?

Your thoughts?

 

[Matty_inkz]

Welcome to the forum and congratulations on your new jeep. It's a beaut!

The last time I checked my mpg I believe I was getting around 22mpg but I haven't driven on the interstate in awhile so I'm sure that's gone down. I also run 33's aftermarket front & rear bumper and a winch but I have the 3.6 so not exactly apples to apples.

You say, you have to really lean on the gas pedal to get her moving. I'm wondering if there isn't something wrong with the turbo system?

Your thoughts?

That's what im wondering but not entirely sure as engine and everything sounds smooth so not a clue. Im here scratching my head, the power is there you can feel it/hear it, its just not "moving" then other times the right drives and scoots just fine. Puzzling. But no where near as bad as my 06 liberty with a diesel. I loved that right out in the sw when I was stationed out there. But she runs strong on the trails here in virginia.but fro some reason on the hwy I can watch that gas gauge just drop and cant find a lick of anything wrong.

 

[4Lo2Yolo]

My 2.0 Turbo JLUR had load range E 35x12.50's, 4:10's, and 8sp auto trans. It could glimpse 30mph on flat land if I drove it with respect and easily get low 20's at 65-75mph when I didn't. With the stock 4:10's it felt zippy like a go-cart. I never regeared it, but with 4:56's I believe it would have thrown you back in the seat a little.

My observations with 4:10's led me to believe that 4:56's would be better suited with respect to acceleration, mileage, and engine braking on trails. With 4:10's it would see 8th gear on the highway on flat land, but in the mountains it felt like it could benefit from a bit more gear like 4:56. Not horribly, but I could tell because I've pretty much been a gear head since since I was a kid. I am almost certain that your mileage will noticeably improve.

My 392 has Bilstein 8100's and 3" AEV lift with HD springs. The springs and shocks make it feel tight like a sports car, and the ride isn't harsh. No appreciable diving under braking, squatting under acceleration, or excessive body roll. I would classify the handling as exceptional. I've owned fast cars, fast motorcycles, and I've spent my share of time on road racing circuits and motocross tracks. It's worth noting that AEV specs 4:56 with their in-house JL builds. From what I can gather, Bilstein's can last 80 to 100,000 miles without service. Fox shocks on the other hand, will require servicing with as little as 30k on them. I have no experience with Fox products.

Lifting a vehicle results in more drag because more air flows under under the vehicle. Every miscellaneous object hanging in the airstream under the vehicle creates a high pressure area upwind of said object, and a low pressure area downwind of said object.

The front fenders of a wrangler are like parachutes, and stubby bumpers let more air in.

Im here scratching my head, the power is there you can feel it/hear it, its just not "moving" then other times the right drives and scoots just fine. Puzzling.

I'm fairly certain that what you're experiencing is just a matter of gearing. I think you'll be much, much happier.

 

[Matty_inkz]

My 2.0 Turbo JLUR had load range E 35x12.50's, 4:10's, and 8sp auto trans. It could glimpse 30mph on flat land if I drove it with respect and easily get low 20's at 65-75mph when I didn't. With the stock 4:10's it felt zippy like a go-cart. I never regeared it, but with 4:56's I believe it would have thrown you back in the seat a little.

My observations with 4:10's led me to believe that 4:56's would be better suited with respect to acceleration, mileage, and engine braking on trails. With 4:10's it would see 8th gear on the highway on flat land, but in the mountains it felt like it could benefit from a bit more gear like 4:56. Not horribly, but I could tell because I've pretty much been a gear head since since I was a kid. I am almost certain that your mileage will noticeably improve.

My 392 has Bilstein 8100's and 3" AEV lift with HD springs. The springs and shocks make it feel tight like a sports car, and the ride isn't harsh. No appreciable diving under braking, squatting under acceleration, or excessive body roll. I would classify the handling as exceptional. I've owned fast cars, fast motorcycles, and I've spent my share of time on road racing circuits and motocross tracks. It's worth noting that AEV specs 4:56 with their in-house JL builds. From what I can gather, Bilstein's can last 80 to 100,000 miles without service. Fox shocks on the other hand, will require servicing with as little as 30k on them. I have no experience with Fox products.

Lifting a vehicle results in more drag because more air flows under under the vehicle. Every miscellaneous object hanging in the airstream under the vehicle creates a high pressure area upwind of said object, and a low pressure area downwind of said object.

The front fenders of a wrangler are like parachutes, and stubby bumpers let more air in.





I'm fairly certain that what you're experiencing is just a matter of gearing. I think you'll be much, much happier.

That's what im thinking ad well. This is my 6th jeep and 3rd one I've built up. I've had it for 6 months, I bought it new with 44 miles on it, and only has 14k miles from driving hwy trips and off road trails in these 6 months of taking it home from the dealer. I k ew bumper weight vs plastic with air dams will add drag and take away what this file cabinet on wheels kinda had going for it, I assumed 33s on 3.45 wouldn't hurt. But add those in with the lift and I agree with you 100%, just hard to imagine before lift and mods I've was getting 27/28mpg consistently on hwy trips but to go from 415 a tank to 280 was a shock, I went 415 a tank to 375/380 with out the stubby bumper and winch, just lift and tires and wheels, but damn adding 120lbs and taking away any aerodynamics would kill another 100 miles off a tank, even with a regear or no regear somthing seems off. I've been a mechanic my whole life minus my 20s when I was in army in the infantry , but still even wheeled hard out there in Washington at Lewis and then in El paso at ft bliss and never took a MPG hit this hard. Being a 2025 JL i cant say its not "not" broken in 13/14k seems broken in for 6 months of ownership, and trail riding everyweekend all weekend. But no leaks, no oil or coolant loss/consumption. No anything other than now I watch the gas gauge drop... I get its a jeep, but over 10mpg loss seems ridiculous. Again. Only other jeeps with less power and tech i saw maybe 5mpg loss. This is over 10.... so idk just crazy.

 

[Matty_inkz]

Update, 4.56 put me back up from 16pm to 23mpg and the jeep moves nicely. Went with yukon for gears and couldn't be happier

 

[Flip]

I'm just curious, how much does a re-gear front & rear cost these days?

 

[4Lo2Yolo]

Update, 4.56 put me back up from 16pm to 23mpg and the jeep moves nicely. Went with yukon for gears and couldn't be happier

That's awesome.

 

[Matty_inkz]

I'm just curious, how much does a re-gear front & rear cost these days?

Mine in virginia ran me around 4200

Sponsored