4.56 vs 4.88
- Thread starter MikeMikeMikeT4R
- Start date
MaddoxPics
New member
You'll want it. I think you can get away with it in flat areas, but anywhere where hills are it's gonna be needed. I haven't put my 4.88's in yet, waiting for my front locker to come, but with just a full front bumper it's definitely rough.
Moving to a numerically higher gear ratio sometimes increase mileage. Not a direct comparison but I had a 2008 Jeep JK with a six speed manual and 3.21 gears from the factory. Still running the factory size tire, (32" MT), I regeared to 4.88 and everyone thought I would blow the motor up, burn so much gas etc. My overall MPG change was... basically nothing. I lost a small amount during high way driving, (around 18 vs 20), but with mixed driving my mileage actually went up, (from 15 to about 18). Although the motor was running higher on the highway it required much less gas to keep moving and around town it was so much better to drive. (I also basically turned my six speed into a five speed plus granny gear which was awesome).
Pinion gear concerns??
For those running the 4.88's, do you have a concern about the pinion gear being weak? I've read some comments from some FJ guys and 5th gens that teeth "go missing".
I am getting ready to order gears and have 285/75's. I'd go 4.56 to be safe... but coming from slow dual sport motorcycles (WR250R), it seems the 4Runner does just fine at higher RPM's as well? (~200rpm difference according to grimjeeper website)
I usually take 1-2 road trips per year and the rest of the time is city, limited highway, some off-roading, and occasional light towing.
If the pinion "issues" are not much of a concern, then the 4.88's really do sound more appealing. I'd love to hear some feedback!
For those running the 4.88's, do you have a concern about the pinion gear being weak? I've read some comments from some FJ guys and 5th gens that teeth "go missing".
I am getting ready to order gears and have 285/75's. I'd go 4.56 to be safe... but coming from slow dual sport motorcycles (WR250R), it seems the 4Runner does just fine at higher RPM's as well? (~200rpm difference according to grimjeeper website)
I usually take 1-2 road trips per year and the rest of the time is city, limited highway, some off-roading, and occasional light towing.
If the pinion "issues" are not much of a concern, then the 4.88's really do sound more appealing. I'd love to hear some feedback!
TheWraith
New member
No issues soo far ... I've trail my rig alot lately. And when camping fully loaded. No issues...
Down side is when I'm loaded down my tranny is hot when going up too steep a hill ... Going to Big Bear I hit like 242 just going up the 18fwy.
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83Mule
New member
Where is the torque peak of this motor.......you want to be at around 3/4 that rpm at your freeway cruising speed. Gear accordingly using tire size and those calculator numbers. This is for best MPG at cruise. I would shoot for what tire and gear will get you to 2800rpm at 70mph if I was re-gearing. 285's seem fine on stock gear for me.
WeedKillrr
New member
285's with stock gearing is great for wheelin. Granted I keep the truck empty except recovery gear and a full-sized spare. But I certainly wouldn't want to tow anything with this setup.
delloro
New member
Do I understand correctly that you attribute higher trans temps to having installed lower (4.88) gears? I would have expected lower temps.
TheWraith
New member
No I attribute my higher temps from climbing a steep grade and being close to 6300lbs when I'm fully loaded. The gears and 35's sure doesn't help either. 4.88's just means the trans is spinning faster than it normally would with 3.73 gears.
I'm putting in a 15,000btu trans cooler hopefully this will control higher temps I've been seeing.
CF_Machete
Senior Member
I went with 4.56 with 295/70/17s. Its a great combo added power and only dropped my mpg by .1 .
I wanted to still be able to get in my garage and the truck feels stockish... a pleasure to drive. However, I can definitely see myself going bigger when I need new tires so I may have been too conservative.
once I retire it to trail only, I may regear again to 5.26 and slap 40s on... but for now its a badass commuter and still fun in the dirt.
I wanted to still be able to get in my garage and the truck feels stockish... a pleasure to drive. However, I can definitely see myself going bigger when I need new tires so I may have been too conservative.
once I retire it to trail only, I may regear again to 5.26 and slap 40s on... but for now its a badass commuter and still fun in the dirt.
delloro
New member
I would have expected the lower gears to lower trans temps, not raise them. Of course I am no engineer.
Which trans cooler?
TheWraith
New member
I went with a B&M # 70273 ... I'll add a selectable fan down the road.
This is the second vehicle I've went with 4.88's ... I had a Tundra 4.7 V8 and the trans died on that one. I think it was a combination of heat ( I tow alot with that truck. Up and down the grape vine. From Sacramento to San Deigo) and me changing oil to a synthetic. And not doing a full flush and drop the drain pan when I did.
So I learn to keep my trans oil with Toyota automatic oil and do Transimission oil change every 3 engine oil changes.
This is all my from experience. And what I've learn.
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Jargonyargon
Junior Member
i know this is an old thread but curious if you put a blower on with 4.88s and what your thoughts are if you did?
Jargonyargon
Junior Member
Curious if you ever went with regear with a blower. And if you did what gearing did you go with?
Jargonyargon
Junior Member
Curious if you have anymore feedback on blower and 4.88s with 35s...I have 4.56s on order and will eventually put a blower on it and trying to decide if this is a better combo than 4.88s with blower. I still have a chance to change to 4.88s if i needed.
My thinking is SC and 4.56s would help keep RPMs down when driving long highway stretches and maintain better road manners but it seems like a lot of people go with SC and 4.88s.
in your opinion, are 4.56s with SC a better option for a rig on 35s that will still see some highway miles before getting to dirt?
Trying to do it once the right way. Thanks
Havik
New member
I've had my Magnuson blower and 4.88 gears for years now running on 35's. I would say that they (4.88s) aren't necessary for this combo, but I also don't mind having the extra torque. Fully loaded down with passengers and gear, I still don't worry about any climb. I took my whole family on a trip from LA to Yellowstone and back in it and it was great. Not the best gas mileage, but other than that, no complaints.
Jargonyargon
Junior Member
Thank you for the reply. With 4.88s and the blower how were highway miles for an extended period of time and RPMs at higher speeds during long stretches? do you even think about it?
This is the only reason I was thinking 4.56s might be a good idea.
Knowing what you know would you still have gone the same route? Thanks
Havik
New member
There are definitely downsides. It gets loud, driving at 80 MPH for extended periods, will start to wear on you. Gas mileage sucks, I mean as low as 8 MPG with the roof top tent, sucks. Having to stop for gas every 200 to 250 miles sucks. I literally take out my URD exhaust and swap back to stock for long trips because the drone gets old quick.
The upsides are no gear hunting on the highway. Lots, and I mean lots, of torque. Fully loaded with gear and passengers I can hit any steep incline and not worry.
I wouldn't even consider 4.88s if you don't have at least 35" tires. Anything smaller and you will hate life. I got the 4.88s before I got the blower (it wasn't out yet), so if I had to do it over, I think I would have gone with 4.56s.
Jargonyargon
Junior Member
Thanks again for the reply. This is solid info that I have been trying to hunt down online. Seems like there's a decent amount of people who regear and put blower on but not a lot of people talk about the tire size they are running.
Trying to figure out what gears to go with has been a serious PITA. I am starting to feel much reassured about 4.56s and a SC for my planned application.
Thanks again
So, let me throw a friendly wrench in the works..
I generally agree with the points Havik made. Yes...mileage sux. Period.
Yes...running 80 mph will make the truck louder than it normally is; not to mention the additional wind noise!
The mathematical difference between 4.56 and 4.88's is only 6.56%.
at 3500rpm the drop is only about 230ish RPM. Your mileage difference, between the two ratios, will be so small as to not hardly notice it at all.
Especially when you consider all of the other variables that can affect mileage on a 4Runner.
FWIW, I run 4.88's and use 33inch tires. I do so because when I hook up the camper I am pulling 45-4800lbs and the camper is 9 feet high. I want ALL of the torque I can get.
Locked in 4th gear, the 4.56's are producing about 1277 Ft Lbs of torque.
By comparison, the 4.88 are producing about 1366 Ft Lbs.
(assuming you are near the engine torque peak in RPM)
I'm a "better to have and not need, than need and not have" guy.
Running 4.88's and 33" tires allows me to run 65ish on the highway at 3500ish RPM and get 10-10.5 mpg pulling the trailer.
IMHO, 4.56 are great for 33' tires, 4.88 work nicely for 34" and 35" should use 5.29's. especially if the truck is 6000lbs or over .
Good luck which ever way you go!
AMLOR
