I would have expected the lower gears to lower trans temps, not raise them. Of course I am no engineer.

Which trans cooler?

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.

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?

Curious if you ever went with regear with a blower. And if you did what gearing did you go with?

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

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.

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

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.

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

I think you are missing the fact that he is or will be supercharged. Torque won't be an issue for him even with much smaller gears.

If I were him and he is going to supercharge, NO DOUBT ABOUT IT! Then I would do that first and see how my rig responds under the conditions I am most concerned about and make a gearing decision then.