Gears? Help!

[MudSweatNGearz]

I have an 88' supercab ranger 2.9, fm146 tranny, 3" body lift, 31' tires, and3.73 gears with a limited slip 7.5. it does'nt have any power at all going up the hills here in WV on the highway id like it to have alittle bit of passing power. I was wondering if 4.10 or 4.56 gears would be better and how much it would hurt my mpg. its getting 12mpg right now i dont think it can get any worse. ill take all the help i can get thanks.

 

[Bent Bolt]

If you're going to change gears, go with the 4.56's. I have 4.10's and it's still not enough.

 

[Wicked_Sludge]

3.73's with 31's is definitely less than an ideal combo (running this myself actually). 4.10's would be good, 4.56's even better.

i wouldnt worry too much about mileage....you might get an INCREASE in fuel economy, depending on what speed you typically run down the highway.

 

[mkpecor]

thats crazy i have the exact same truck but on 33" tires and i get 17 mpg, running 3.73 gears, any wayz the 4.10 would do just fine for 31"s

 

[Evan]

Just be warned, you can go too low. I have 5.13s and 33s, and it's too low for highway driving. Plan on swapping on 35s to fix the problem.

 

[Hahnsb2]

I have 4.10s with 31s and they are about perfect, soo much better than 3.45s. 4.56 would be nice sometimes but I think they would be too low for normal driving. And 4.10s will help your milage. 12 mpg is pretty low, either you're driving it wrong or something is broken. I pulled 15MPG with 3.45s and 31s average, I still get the same now but I drive it like a rented mule a lot more with 4.10s.

 

[Thumper113]

thats crazy i have the exact same truck but on 33" tires and i get 17 mpg, running 3.73 gears

Yes, but is your speedo/odo corrected for the 33" tall tires while running 3.73's? If not, that's not your actual mpg.

 

[Hahnsb2]

Yes, but is your speedo/odo corrected for the 33" tall tires while running 3.73's? If not, that's not your actual mpg.

He would actually be getting better millage because hes going farther than what his speedo claims because of bigger tires.

 

[4x4junkie]

2.9L + 31s = 4.56 gears.

4.10 would be great for a 4.0L, but the smaller engines like a bit more RPM.

 

[Sunk]

I have the same setup right now, and its not too bad except on the highway. I get 15-16 consistently.

As my sig says I'm going to 4.56s and 33's, I think that comes out to just a little deeper than stock.