axle ratio & tire size

[want new truck]

I am planning on buying a 2015 ram 1500. if I am increasing the tire size what do I need to do as far as gear ratio goes?

If it helps, I think I am going to put 34" tires on it and I don't care about fuel economy just acceleration power and overall performance.

 

[Jerry1984]

3.92 gears.

 

[want new truck]

do I need 3.92 gears in the front aswell?

 

[ncgrl1]

YES...If its 4wd, front and rear must match.

 

[want new truck]

thanks. would it be better if I got a higher gear ratio than 3.92 all together?

 

[ncgrl1]

Hopefully others will chime in but you can go to a 4.10 or 4.56, but you will have to do some machine work to get things to work with the 4.56. I'm not sure if the 4.10 is a direct replacement or if you would have to do some extra work on it also.
Check with Matt at Moe's Performance...

 

[sicmadek]

with a 8spd and 3.92 i doubt you will have a problem with 34" tire

 

[Hemi450hp]

^^ 8 speed and 3.92's is more than enough gear for 34" tires.

 

[want new truck]

ok thanks everyone

 

[cqt]

I've got a '14 ram with 8 speed and 3.21 with factory 20" rims. Factory tire height is 33" so I would imagine 34 would be no issue

 

[xrsman]

My 3.92's seem to work fine with my 35's. Still lots of snap and honestly my MPG's aren't that bad. This pic was a a fill up from 3/4 of a tank to full. I'm happy with that! Most of it was around 80 km/h following slower people in the snow but I was in 4wd the whole time, that will make a difference. Had my dad's 500 lb sled in the back today and even then truck didn't know it was there. I know it isn't much weight but with the 35's I didn't know how the truck would react. Your 34's with 3.92 gears would be great!