4.88s on Stock Tires

[Blazing Saddles]

Do you track fuel economy each tank or just check the dash readout? How's fuel economy on day to day drive around town with highway mixed in? I live in an area with lower speeds and some good grades as well, so the 4.88's are interesting

I am lazy and just use the readout. I average about 17mpg or so around town. According to the system, I am averaging over 18 total and my trip yesterday, which was a mix of highway, mountain roads, and traffic, was over 20.

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[jbcrane]

I have seen various threads on here about how the new 4.88 axle option would be with stock tires. I received my Jeep a few days ago and wanted to give my input from driving with them. I know there are people on this forum that could fabricate new gears from a clothes pin and a beer can, so this is more for those of us without tons of knowledge or experience with various gears/tires. I also did not drive on the standard 4.10s to give a comparison, but here goes.

My driving needs are drastically different than many people, but for people in my situation, I hope this helps. For context, the main road into town is 55 and I drive around 60 on it. Most of the roads around me are 35-45 max and honestly if you go any faster you will go careening down a mountain slope. That being said, here are my observations so far:

I use 6th gear a lot. I can comfortably be in 6th and accelerate up hills as long as I'm going around 55+. Driving back home from Atlanta and going about 65, I was at ~2200 RPM and was getting 20+ MPG. I really love how much power it seems to have around here in the hills. Reading some various posts about the manual trans and the 3.6, I started to wonder if the engine would feel anemic. It does not.

If your driving habits would be more interstate or 75mph or such, I wouldn't recommend them on stock tires. I have no plans to increase the tire size, personally. However, if like myself, you live in an area where almost all the roads are inclined and normal speeds are lower, this may be an option you might want to look into.

This is helpful. Thank you. I’m looking at 4.88’s for my 3.6L 6-speed manual here in Colorado. Just moved to 315/70’s with the Mopar lift. I’m considering it to get back power at altitude, to regain 5th and 6th gear and to ease clutch engagement starting from a dead stop or on incline. I imagine I’ll see a slight bump in mpg but it’s not the primary reason. Having real world feedback like what you have provided is very helpful. Thanks again.

 

[grimmjeeper]

This is helpful. Thank you. I’m looking at 4.88’s for my 3.6L 6-speed manual here in Colorado. Just moved to 315/70’s with the Mopar lift. I’m considering it to get back power at altitude, to regain 5th and 6th gear and to ease clutch engagement starting from a dead stop or on incline. I imagine I’ll see a slight bump in mpg but it’s not the primary reason. Having real world feedback like what you have provided is very helpful. Thanks again.

I had 4.56 with the 3.6, 6 speed manual and 315/70R17 tires in my JK. They were ok in the low elevation flatlands but after moving to Denver I really wished I would have gotten 4.88s.

 

[word302]

This is helpful. Thank you. I’m looking at 4.88’s for my 3.6L 6-speed manual here in Colorado. Just moved to 315/70’s with the Mopar lift. I’m considering it to get back power at altitude, to regain 5th and 6th gear and to ease clutch engagement starting from a dead stop or on incline. I imagine I’ll see a slight bump in mpg but it’s not the primary reason. Having real world feedback like what you have provided is very helpful. Thanks again.

4.88 should be the sweet spot for those tires. If you think you will EVER go to 37" tires I would highly recommend 5.13s with the manual.

 

[Krondor]

4.88 should be the sweet spot for those tires. If you think you will EVER go to 37" tires I would highly recommend 5.13s with the manual.

 

[grimmjeeper]

4.88 should be the sweet spot for those tires. If you think you will EVER go to 37" tires I would highly recommend 5.13s with the manual.

Agree 100%

 

[Gossamer]

Picking up my JLUR with 4.88’s tomorrow. I'll probably need a week or so before I can give an evaluation. I took a 5 year hiatus from manuals, have about 400,000 miles over 25 years in them. Can't wait to row my own again!

 

[Jmos4]

Hi,

Just got my 22 JLUR 6mt 4.88's and has been mentioned 1st is good on a incline, but still need to shift into 2nd before you get out of the intersection, this is both with the stock 33's and now 35's. Just got 700 miles on it and still feeling it out.

Regards,
Jim

 

[jbcrane]

Picking up my JLUR with 4.88’s tomorrow. I'll probably need a week or so before I can give an evaluation. I took a 5 year hiatus from manuals, have about 400,000 miles over 25 years in them. Can't wait to row my own again!

There's' nothing like it. Congrats and welcome back.

 

[BuyHold]

Picking up my JLUR with 4.88’s tomorrow. I'll probably need a week or so before I can give an evaluation. I took a 5 year hiatus from manuals, have about 400,000 miles over 25 years in them. Can't wait to row my own again!

Any update on what you think about the 4.88s? 16 weeks in and I personally would love to hear your impressions thus far.

 

[Blazing Saddles]

Any update on what you think about the 4.88s? 16 weeks in and I personally would love to hear your impressions thus far.

I still love them. I think it is the perfect pairing with the manual and the stock KO2s. I am almost to 2k miles, I know I don't drive as much as some, but so far it has been great. My wife owns a sport with the automatic and I prefer to drive the manual. If I was forced to lodge a complaint, it would only be that 1st is generally unnecessary. I find I use it more now than when I first brought it home, but I still take off in 2nd most times. Another thing to take into consideration, I own a 2dr. Not sure if that makes a huge difference, but anecdotally, I notice more 4dr owners unsatisfied with the manual than 2dr. Also, I believe you can get the 4.88s with the auto now. It would be nice if someone with that configuration would add their experience to the thread as well.

 

[BuyHold]

I still love them. I think it is the perfect pairing with the manual and the stock KO2s. I am almost to 2k miles, I know I don't drive as much as some, but so far it has been great. My wife owns a sport with the automatic and I prefer to drive the manual. If I was forced to lodge a complaint, it would only be that 1st is generally unnecessary. I find I use it more now than when I first brought it home, but I still take off in 2nd most times. Another thing to take into consideration, I own a 2dr. Not sure if that makes a huge difference, but anecdotally, I notice more 4dr owners unsatisfied with the manual than 2dr. Also, I believe you can get the 4.88s with the auto now. It would be nice if someone with that configuration would add their experience to the thread as well.

Thanks for the update. Sounds like your opinion of 1st gear on 33s with 4.88s is that it is simply a crawler gear. I personally wouldn't mind that at all. Glad to hear you are still liking the set up.

However, regarding your request to have Auto owners share their experiences here.... please, let's not. If we open that door this thread will be flooded with comments about how much better the auto is, how much faster it shifts, how they roll around on 42s all day without regearing, how they can drive it even without the leg they got amputated due to diabetes. Then they will collectively wail out questions about why any one would buy a MT in this day and age but then at same time say how much better ICE-driven cars are than any electrified transmission less vehicles ever will be. OK, this is all a joke... except that I see no need to hear about the auto with 4.88s.

 

[Go_Galt]

Any update on what you think about the 4.88s? 16 weeks in and I personally would love to hear your impressions thus far.

I've had mine for almost two months now. Driven it with the stock 33s as well as 37x12.5 KM3s and 37x12.5 KO2s (which are on now).

It's extremely engaging to drive on the stock 33s (IMO almost 'too' engaging'. I described it in another thread as 'manic'). The people that say you're shifting into third as you clear the intersection are not exaggerating.

The gearing is of course short, but it's also a little awkward. First is so ridiculously short it almost qualifies as a 'granny gear', though second still requires a little too much clutch slipping to take off with (again, IMO. There are others in these and other threads that disagree). I would indeed take off in second if I'm on a very slight decline, or slow-rolling a stop sign at ~1 mph. But it's just a tad too tall for doing it all the time from a stop.

Highway cruising on the 33s was fine, IMO. But I don't drive fast. 75mph in 6th was turning about 2,800 RPM. A little zingy, but also where the Pentastar is making some power, so doing relaxed passes and climbing smaller hills was easily done in 6th without downshifting. Keep in mind I'm not far off from sea level.

I really like how it drives on 37s, as it definitely feels more 'natural'. 37s did noticeably slow it down, as you'd expect, but not to a point that is a problem for me. Still pulls very respectably in first and second. Third still easily merges you on the freeway. I do kind of miss how quickly 2nd gear would absolutely RIP you to 40mph on the 33s though.

Overall I think almost every manual driver is going to really, really like getting factory 4.88s. The only way I'd recommend against it is if you absolutely, positively, knew you were going to stay with 33s, AND don't think you'd like the driving experience of how short first and second are with 33s.

I never got a chance to try mine with 35s, but I think that's probably a sweet spot for this trans and 4.88s.

Also- these experiences are with a light 2-door.

 

[AcesandEights]

So glad I went with the 4.88. In fact, it is the reason I sold my 2021 JLR and bought an identical 2022 JLR with 4.88.

 

[BuyHold]

I've had mine for almost two months now. Driven it with the stock 33s as well as 37x12.5 KM3s and 37x12.5 KO2s (which are on now).

It's extremely engaging to drive on the stock 33s (IMO almost 'too' engaging'. I described it in another thread as 'manic'). The people that say you're shifting into third as you clear the intersection are not exaggerating.
...

Thanks for sharing. Good review.

On a separate topic, you say you were on KM3s and are now on KO2s. Why the change?

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