I was looking through the forums at various posts about people wanting to tow things, and going over the primary posts of '3.55 is fail if you want to tow.. go 3.73 or 4.30' (Though, those are referencing gas engines).

While my truck still hasn't been delivered, i did finally get the window sticker to validate what we ordered way back in September. (Thanks forums! This url is awesome.. as long as you remember to input your VIN in upper case :P http://services.forddirect.fordvehic...icker.pdf?vin=[YOUR VIN]
)

Anyway, when I built my truck with the dealer they only had the paper book to build it as it wasn't in any online system yet since they were still tooled for the 2012 models. We ended up selecting the 3.55 ELD.

When I go to the builder tool now, the only options with diesel appear to be 3.55 LS and 3.55 EL for a 4x4 F250.

If I drop my trim package from platinum to something else, 3.31 becomes an option as well.

Is there just no need for a 3.73 or 4.30 when using diesel? I don't see a way on the build tool to with any F250 setup to get larger than 3.55.

Pardon my ignorance.. trucks + diesel are both new to me

 

for 2012 and 2013 I am under the impression that the diesel only gets the 3.55. With the new 6 speed and the 6.7 the way it works out is different than with a 3.55 and the torque shift 5 speed or the old school 4 speed. Don't worry about it, the gearing in the trans along with the ginormous amounts of trq in the 6.7 don't require the different axle ratios like they used to.

 

The 6.7L gets the 3.55 or 3.31 ratio on the SRW trucks. Step up to a DRW F-350 and you can get 3.73s. Step up to an F-450 and you get 4.30s.

 

Exactly as Redford says. I'll add also that yeah...you really won't need more. I have the 3.31 in mine, and it tows my 5th wheel so nice, I doubt you would be able to tell the difference with 3.55. I had the 3.73 on my '08 with the 6.4L, and this truck still leaves the '08 in the dust. People don't believe it, but it really is a tremendous power plant in these new trucks. You will be fine with the 3.55...trust me!

 

I have the 3.55 in my f250 and I think it's a great setup. Tows great.