What axle gearing

[Scott39]

What gears should I go with in my diffs when running a 6.5turbo diesel, and 38"-40" tires?
And what is the best RPM`s to run the engine down the Highway, and the redline of a 6.5turbo diesel?
Thanks,
Scott

 

[imiceman44]

What gears should I go with in my diffs when running a 6.5turbo diesel, and 38"-40" tires?
And what is the best RPM`s to run the engine down the Highway, and the redline of a 6.5turbo diesel?
Thanks,
Scott

I think with those tires you want 4.56 gears.
1900 to 2000RPM is good fuel economy IIRC.
3600RPM is redline or actually governor speed limit.
IceMan

 

[Scott39]

I think with those tires you want 4.56 gears.
1900 to 2000RPM is good fuel economy IIRC.
3600RPM is redline or actually governor speed limit.
IceMan

3600RPM, wow! I`m use to the big semi`s I drive at work, max rpm is around 2100, but they are governed at 1950rpm.

 

[imiceman44]

3600RPM, wow! I`m use to the big semi`s I drive at work, max rpm is around 2100, but they are governed at 1950rpm.

Yeah this ia a V8 high revving.
I have a 6 inline and 1900 is my governed speed.

 

[tRustyK5]

3600RPM, wow! I`m use to the big semi`s I drive at work, max rpm is around 2100, but they are governed at 1950rpm.

I run 4.56's with 39.5's (no overdrive) and it spins about 2600 rpm on the freeway. It doesn't mind those R's at all, but I do. It's loud and it hurts fuel mileage...

The 6.2 does respond really well to deep gears, very similar to a small block that way.

Rene