Eco2014

Stopped by the dealer today for a oil change and tire rotation. Was killing time so walked around the lot. I would say 99% of the trucks on there lot had 3.31 gears on the trucks? I maybe saw 2 with 3.55 gears. What's up with this?

crgettle

Noticed the same thing on lots around me. I think it's a combination of the 2015`s being that much lighter, as well as the 5.0 engine putting out more horses and torque.
So the 3.31 rear end isn't a dog like it use to be and is rated to tow almost the same as the 3.55 rear end.
A few people have mentioned on here already that the 2015 3.31 is more or less the equivalent of the 2014 and older 3.55.
That's just an opinion. Not factual.

Eco2014

That very mane be true. I've always been a fan of 3.55 gears. It's a all around good gear. The 3.31 is great for highway use, but get to pulling heavy trailer mite be a problem?

Killav-TT

If you do the math, The 3.31's with the 18" wheel and tire option (265/60/18) and the 3.55's with the 20" wheel and tire option (275/55/20), the RPM's are only apart by about 58 RPM (the 3.55's with the 20's spin the engine a little higher).


So, having the shorter tires (18's) with the 3.31's wouldn't seem like a huge penalty. Plus the 18's are a bunch lighter too. Less unsprung weight is always a good thing. At the dealers around here, I have noticed most trucks with the 20" wheel option equipped with 3.55 gears. But not all of them.

jdp530

Most people probably don't tow really heavy trailers so the 3.31 will give them the best mpg on the highway. But, I usually prefer the 3.55 locking axle for better towing capability and to get up boat ramp, through the mud, etc.

After looking at many of the trucks a few weeks ago, I get the impression that dealers have a bean counter ordering the trucks. Doesn't make any sense to order a truck with tow pack, 3.31 gears without locking axle, and without a brake controller.

My XLT CC 5.0 has tow pack, 302 equip grp, 3.55 EL axle, nav, backup cam, but no brake controller.

BStrummin

Max tow is 3.55 locker. My XLT has 18's too. I don't pull a lot but we do have a TT that gets pulled into the mountains several times a year.

Also I'm not sure if this is related but I'm getting +2 mpg in my 15 than I did in my 14 that had a 3.73 but otherwise was identical (other than model year and possibly weight).

ddeevers

3.55's are not easy to find, try finding a 3.73 truck in your area.

T_R

Mine came with 3.73. I like it so far.

Happy4758

My new 2015 just got brought in yesterday. 5.0 and it has the 3.73

Josh2021

It took me lot of searching local lots to find the truck with everything I wanted(3.55, sport, xlt, tow, 36g fuel, 3.5 eco, 302a). Most had 3.31 and a few with 36g tank, it was almost like finding a needle in a haystack.