Anyone wish they regeared with 4.88 instead of 4.56 ???

I have an 08 DCLB w/ 6" lift and 35" tires; I'm on the verge of regearing with 4.56 because I spend 80% of my time in city and freeway. Has anyone in my similar situation that has regeared to 4.56 wish they would've gone with 4.88? I love the idea of having that extra torque, but I drive 75+ mph everyday and the thought of the 4.88 scares me. I've read ALL the available threads regarding gearing, I didn't see any responses of people who went with 4.56 wishing they chose 4.88. I'm curious how you now feel after driving on it for a long time and the new-ness/fun of the the 4.88 power wears off. Thanks guys!

 

Have you seen the gear ratio calculator on http://www.grimmjeeper.com/gears.html It can figure out your rpm at the speeds you want to travel if you put in your 5th gear ratio, tire size, and diff ratio. I wouldn't be surprised if you could get pretty close to simulating 4.88 by shifting into fourth. If I did the numbers right, you're at 1934 rpm at 75 now (with 3.73 gears) and you would be at 2530 with 4.88's. I have 33's and 4.56's and I'm at about 2500 at 75mph. I wish the truck had another gear. But I don't drive on the highway much.

 

Bump

 

I've talked to both sytfu510 and wicked 2007 about this. Since they went up to 35s, they've thought 4.88s would have been better

 

I sometimes wish I would've gotten 4.88s instead of my 4.56s but but I am in the same boat as you with 80-90% road driving and the 4.88s tend to be a little weaker. So overall I'm glad I stuck with my 4.56. 75+ speed would absolutely kill your MPGs with 4.88s. I already get around 12-14 with 33s and 4.56.

 

4.88 is very scary for highway speeds. My Jeep has them and I never go faster than 55 with it on the highway at all.

 

Thanks for the responses gentlemen. And thanks for your opinions. Those with 35's and 4.56, do you feel that the truck have enough power around town and climbing hills? I don't want to spend all this money to regear, only to be unhappy with 4.56.

 

If my truck was on the trail most of the time 4.88's would obviously be ideal. But since my rig sees mostly hwy, 4.56's are perfect. Lots of power around town and decent for hills too. If you're going to be on the hwy a lot tho, I'd stick with 4.56's IMO.

 

Agree ^


I would go with 4.56's.

That is what i am running right now.

mt speed 6 about 65 @ 2500 rpm.

 

So do the rpm's rise vs stock gearing? Driving 98% on road and most of that being highway, would it make sense to regear it when I'm looking for fuel mileage? Power would be nice but I'm really just trying to get better mileage. I dont want to spend $2k regearing and end up losing gas mileage. To my understanding, my rpm's will rise at highway speeds vs the rpms of stock gearing, which means more fuel is burned? Please correct me if I'm wrong.

 

What are your MPG's at right now?

These trucks prefer lower RPM's for better gas mileage.

I re-geared for bigger heavier wheels anticipating better MPG's and it didn't improve at all.

RJM

 

My guess is around 13-14 mpg. I havent actually calculated it yet but I get about 210 miles to a tank. Im running 35's.

 

bringing this back from the dead. you running 35”s at this time of that 4.56 ratio?

 

4.88 hands down. I have 4.56 and 35’s now. Wished I had gone 4.88 when I had 33’s as well. Your fuel mileage will be affected more by destroying your aerodynamics with an after market bumper and big tires than by a few extra RPM’s. Even at 75/80 my auto hunts between 4th & 5th with slight grades or modest headwinds.

 

you got front and rear armor?
Are you More off road than highway?
From your mods listed it looks like you’re packing around an extra 500lbs at least...

 

would you agree with this?

 

I have front bumper, winch w/ synthetic line, rear bumper w/ swingouts, sliders, aluminum skids, shell, plus drawer, fridge, rec gear - and it’s a limo. So no doubt I’m heavy. I do a fair amount of offroad, but also cover 25-30k miles per year, so it’s mostly highway and mostly 75/80 mph. The difference between 4.88 and 4.56 is pretty minimal. I don’t think you would ever regret having a slightly lower ratio.

 

I’m pretty much stock, no armor. just a lift and dirty fives. Most likely won’t go up in tires size.
Would like to eventually get a hidden winch for the front bumper, nerf bars and a soft topper canopy. While pulling a boat in the summers rarely.
I drive 90% of the time around town and hwy commuting to work. Off roading sometimes just for camping and shooting not much crawling.
The high revs are what is deterring me from 4.88s I’ve done the math and a shit ton of research online and both calling diff shops, 4.56 seems perfect for it.

Just can’t wrap my head around which ratio is best for added weight (family, gear, towing, running boards and hidden winch) aerodynamics with added tire weight. Not to mention living in a some what hilly area. Majority of the time it’s just me driving to work

 

I’m in a 6-speed manual so that changes a few things in regards to final gear ratio. I’ve got 33’s, full armour, roof rack and higher bed cap. I’m pretty heavy and un-aerodynamic when loaded up. I have decided that 4.56’s will be the best for my situation. I will be slightly over geared but I’m ok with the higher rpm on the highway (~2800 at 70mph) to have better drivability for a non daily driven, camping/off-road rig.

The decision I had to make was between 4.30 and 4.56 gears. At 70mph the rpm difference between the two is only approximately 150. I can see this being the case for your situation with the 4.56 vs 4.88 gears. To me, the minor (higher) difference in rpm was worth the better drive, acceleration, etc.

eta- truck for reference.

 

I wouldn’t think it would be much different in an automatic? I won’t have nearly as much weight as you and as I will daily driving. I may change my mind in a day but it sounds like 4.56 would be best for me.


I appreciate it and thanks for sharing, save the Manuals! Nice truck btw!!