3.31 Rear axle ratio?

[Disnitch]

Anyone have a truck with a 3.31 rear axle ratio? I'm looking at a bunch of 2010 trucks and some have 3.31's and some have 3.55's. Is there any noticeable difference between the two when it comes to acceleration or MPG's. I would think MPG's would be a little bit better but these trucks vary so much from one to the other I'm not sure it would matter. DPF delete will happen shortly after purchase and down the road I will add a levelling kit and some 35's.

[Dave]

I didnt know you could get a 6.4 with 3.31's

[Disnitch]

I didn't either until I started looking at window stickers... They are XLT models with 17" wheels so that might be the reason why. I think the 18" wheels have 3.55's and the 20" wheels have 3.73's.

[08stroker250]

3.31's would be awesome on a RC/LB race truck with like 28-30" race tires. I can't imagine them being good on a CC/SB though, but who knows? I want 3.55's in my truck, but I can't justify the cost of doing for the benefit in MPG and track times.

[Disnitch]

I'm never going to tow heavy with this truck and the biggest tire I'll throw at it is a 35, but it is a CC/SB. I'm basically deciding between a XLT with the FX4 package and 3.55's, or an XLT with the XLT convenience package and leather with a 3.31 rear. I can always get Katzkin leather for the first truck for $645 off ebay so either one will work. I'm going from a V6 F150 work truck so it's a HUGE upgrade either way.

[turbo kidd]

I have the 20" wheels and I have the 3.55 gears too....I have a 2010 f-250. I'm not sure the 3.55's get you that much better fuel economy? Maybe on the flats for long runs, but overall, I don't see much of a gain.

[LFD132]

Originally Posted by Disnitch

I didn't either until I started looking at window stickers... They are XLT models with 17" wheels so that might be the reason why. I think the 18" wheels have 3.55's and the 20" wheels have 3.73's.

2008 models offered the 3.73 gear. I believe the 2009-10 f350 and up is the only trucks that come with 3.73 gears since they started offering the 3.31 and 3.55.

[Ghamilton]

My 2010 F350 has the 3.55 gears with 20" wheels. I wouldn't mind having the 3.73s though!

[turbo kidd]

Originally Posted by Ghamilton

My 2010 F350 has the 3.55 gears with 20" wheels. I wouldn't mind having the 3.73s though!

Me too! However, the 3.55's have been just fine for what I tow.

[GC Builder]

Originally Posted by 08stroker250

3.31's would be awesome on a RC/LB race truck with like 28-30" race tires. I can't imagine them being good on a CC/SB though, but who knows? I want 3.55's in my truck, but I can't justify the cost of doing for the benefit in MPG and track times.

Huh?? Don't you breath and live the track Jeff!!