Re-gearing for Km2s : Suggestions Wanted

[97RunnerV6]

My stock 3.4L V6 is going to be turning LT255/80R17 BFG KM2s soon (with the additional help of the 3' EMU Suspension Lift) I am ready to re-gear but I am pondering whether to run 4.11's or 4.56's, my mileage is most important because it will be mostly street driving for at least one more year. Is 4.56's too low?

 

[Jon]

That calculates to 33x10r17. I have 4.10 stock and 33's, no gearing needed it still has plenty of power.

 

[Rc4r]

savage offroad sugest 4.88s you might think thats to low. so id go with 4.56s

 

[YotaZach85]

What gears do you have now? Year, trans, 2 or 4wd???? If you have 4.10's (most common ratio) 4.56's really arent worth the money, I made that mistake with my Tacoma and I was pissed when I drove it after the re-gear. I would stay stock if you're more worried about mileage, go with 4.88's if you want power.

 

[GX4SEVEND]

I'm on 315's and its not that bad. Whats the total cost to re-gear? If fuel economy is your concern....this is the wrong vehicle. Its probably not worth it to regear as it would take a long time to reep the benefits.

Just my opinion

 

[brian2sun]

4.88s for a daily driver.
5.29s for an off road rig.

That's assuming you're auto tranny. Like YotaZach85 said, don't bother with 4.56s. I completely agree that they will not be worth the money. If you're a manual, 4.56s will be good though.

 

[99runnerwa]

my rig came stock with 3.90 gears (i know im a few hundredths off but close enough with out looking it up again) and i went with the 4.88. the final drive ratio ended up being just a little lower than stock but it works great on highway and off. And my mileage didn't take that big a hit.
A good calculator to compare your final drive ratios
Gear Ratio Calculator
And here is a link to figure out the specs of your rig
Toyota 4Runner History 1999

 

[Rc4r]

Great sites ^

 

[Mr. Leary]

What gears do you have now? Year, trans, 2 or 4wd???? If you have 4.10's (most common ratio) 4.56's really arent worth the money, I made that mistake with my Tacoma and I was pissed when I drove it after the re-gear. I would stay stock if you're more worried about mileage, go with 4.88's if you want power.

I concur.

 

[YotaZach85]

I'm on 315's and its not that bad. Whats the total cost to re-gear? If fuel economy is your concern....this is the wrong vehicle. Its probably not worth it to regear as it would take a long time to reep the benefits.

Just my opinion

Parts alone cost me ~$600, I did the install myself so I didn't have to pay for labor but labor can be $800 or more.

 

[Rc4r]

I would stay stock if you're more worried about mileage, go with 4.88's if you want power.

how much of a power difference do you think i would see with 4.88s?

 

[YotaZach85]

how much of a power difference do you think i would see with 4.88s?

I can't say from expirience but I hear it's a nice little bump from stock, it'll be really noticeable going from stock gears and 33's to 4.88's. Hopefully someone with 4.88's will chime in on that question.

 

[Nelsonmd]

Lots of guys here share the opinion that if you re-gear, go 4.88 or 5.29. This also allows you to go bigger on tires in the future and have decent gearing, good if it might be a trail rig in the future.

Also, 4.10 and 4.30 are the common ratios for 4runners, so if you end up having to replace something in the future, a 4.1 or 4.3 will be alot easier to find than a 4.56.

To me, 4.56 wouldn't be an option because it just doesn't seem to be very common. If you want to gear up a bit higher than 3.9, then I'd say go for 4.88, but if you are afraid of that high a gearing, see if you could find a steal on salvage 4.3's. You could possibly get them for super cheap if you are patient. Most guys here will probably say that won't make a noticable difference going from 3.9 to 4.3, but you could find 4.3's with a locker, which is another big plus.

 

[brian2sun]

how much of a power difference do you think i would see with 4.88s?

Hopefully someone with 4.88's will chime in on that question.

With an auto tranny and coming from 4.10s, 4.88s will only give you back the power you lost from the 33s and that's it. But if you plan to add hundreds of lbs. in bumpers, sliders, armor, tools, a winch, etc.., then 5.29 is a better ratio - even if it's a DD with all that stuff. My 4.88s made up for the tires only - not for the weight of my armor. My truck now has the power of a stock 4runner pulling a 700 lb. trailer all the time. I think a SC will be coming soon..

Lots of guys here share the opinion that if you re-gear, go 4.88 or 5.29. This also allows you to go bigger on tires in the future and have decent gearing, good if it might be a trail rig in the future.

Also, 4.10 and 4.30 are the common ratios for 4runners, so if you end up having to replace something in the future, a 4.1 or 4.3 will be alot easier to find than a 4.56.

To me, 4.56 wouldn't be an option because it just doesn't seem to be very common. If you want to gear up a bit lower than 3.9, then I'd say go for 4.88, but if you are afraid of that low a gearing, see if you could find a steal on salvage 4.3's. You could possibly get them for super cheap if you are patient. Most guys here will probably say that won't make a noticable difference going from 3.9 to 4.3, but you could find 4.3's with a locker, which is another big plus.

Fixed it for ya^^. 4.88 is a higher number than 4.10, but 1:4.88 is a lower gear ratio than 1:4.10.

I agree with your statement above. And actually, going from 3.90s to 4.30s will be noticeable, however it still isn't a good ratio for 33s on our trucks. The elocker is nice, but after you pay to regear the front diff to match the 4.30s, it's not much cheaper than a rear ARB locker and the gear ratio of your choice.

 

[97RunnerV6]

Thanks guys for your help I hadnt thought about going with 4.88's but that was before I knew I had 4.10's. I really only drive about 25 miles a day so I think it wouldn't make too much difference in mileage.

 

[Nelsonmd]

Fixed it for ya^^. 4.88 is a higher number than 4.10, but 1:4.88 is a lower gear ratio than 1:4.10.

I agree with your statement above. And actually, going from 3.90s to 4.30s will be noticeable, however it still isn't a good ratio for 33s on our trucks. The elocker is nice, but after you pay to regear the front diff to match the 4.30s, it's not much cheaper than a rear ARB locker and the gear ratio of your choice.

Whoops... Good thing we aren't talking about viscosity, that's even harder to remember...

 

[Rc4r]

how much will I see power wise with 5.29s

 

[Mr. Leary]

how much will I see power wise with 5.29s

Lots. The RPMs at highway speed with 5.29s will be slightly lower then what they are on stock gears with OD off. Comparatively, it will feel like a sports car.

There are some drawbacks however that I have discovered during my research... you will likely not exceed 16mpg and the pinion is very small... kinda worrisome although I have not seen any cases of a grenaded ring & pinion on anything less then 37" tires.

 

[toyxterra]

go 4.88s for the 33s it will do a lot better than u think i have 35s and 5.29s and i get better milage now than i ever have plus the power to back it its great having both. dont go to high and wish u had gone lower...

 

[04rnr]

heres a nice chart here: 4Lo.com :: Gear Ratio & Tire Size Chart