Let's talk about re-gearing

I’ve been contemplating regearing since getting 285s for better MPG. I keep reading it can help with MPG so I figure if I get 1-2 MPG better it would pay for itself over the next 100k miles. The power loss is minimal and I drive like a grandpa so all good there.

I see many haven’t seen better MPG after regearing which brings up something I’ve been confused about for a while. This gear chart shows “Less power/Better MPG” with 33” tires and the stock 3.91 gears. With 4.56 gears it shows “More power/worse MPG”.


I’m confused as to why one can potentially expect better MPG after regearing when this chart says otherwise.

 

Because the charts estimated RPM’s are based on 65mph which with stock gearing I get my best MPG around 18.5mpg with 285/75/r16’s.

Most of my driving is city short trips (reverse results of your chart) which the regearing would be Optimal for me because my mileage is awful, but its not in the works due to the approx. $4k price tag (new parts labor by a shop for 4x4).

Issaammi has done a swap on his 4x4 from Tacoma Diffs which are plug and play for DIY. Think you’ll lose the LSD is the only negative.

 

I see and 18.5MPG? That’s amazing!

 

Yeah. Straight highway 65mph its doable. City is 10-14mpg depending on winter blends, cold weather, and summer temps.

I’d love to regear if it was le$$.

 

Nitro gears are about $1,100 and to add an ARB locker is $1k more. Does it cost $2k for labor?

https://www.nitro-gear.com/Toyota-7-5-CS-8-4-Nitro-Gear-Package-p/gptaco96-04-select.htm

Edit: Found them for about $100 le$$ $980

 

Have never received a direct quote, but based on prices I’ve heard others quote (professional shop etc).

Yeah someone can do it for less $$$ and in half the time will be others responses. These require shimming and professional installation when installed from scratch. Only way I’d attempt is doing that method of Issaammi which is plug and play componenets.

 

That chart is not applicable to FGTs....2000-2004 have a 4sp A340 with a .705:1 ratio in 4th (3rd is 1:1) and 05-06 have 5spd a A750 with .716:1 5th gear ratio (4th is 1:1). Whether you can expect better MPG depends on how much you regear and if your ratio of hwy/city driving.

If you do alot of stop/go, shorter gearing will get your better mpg (to a point)...if you do mostly hwy, taller gearing will get you better mpg (to a point). I went from 31 to 33.2, which had the effect of raising my gear ratio from 3.91 to 3.65...unfortunately, most of my driving is stop and go, so it killed my MPG.

Remember, when going to a taller tire size you want your gearing to be at list a bit shorter than stock, to compensate for increased wind resistance from the increased vehicle height.

This is from another post I did on gearing...

Best gearing tool out there....you only need to do Steps 1, 4 and 5 for what you want to figure out....

http://www.grimmjeeper.com/gears.html

 

I was quoted $1800 for nitro gears front and rear from East Coast Gear Supply back in 2018 for a Tacoma...so that's a ballpark figure. Don't forget with the ARB you also have to add cost for an onboard compressor (250+) and the labor to install it....

 

Chart does not take into account any O/D. So not applicable.

 

Agree with @speedtre, Chart takes zero engine or vehicle weight (sprung and un-sprung) characteristics in to play. It assumes all engines operate with the same efficiency ranges. May not be true for either the V6 or V8 Tundras. Changes with different torque curves and different wheel tire combos, aerodynamics, DRIVING STYLE, and overall vehicle weight. Also have to adjust those MPG's for actual mileage and not speedo and odo miles if you regear and don't correct the speedo.