caperJ

I am not the only one! yeah! 2.10 3.55, 2011 3.73, 2013 3.55, 2.15 3.55 and worst yet 2018 3.31. !0 speed and 3.31 still sucks no matter what papers you put to it. You have to own each to know the difference and the 10 or 6 speed will not make much difference.

butcher73

@ caperj... what is the point of the original post?
1 - you got stuck in the snow?
2 - mpg's suck w/ the rear end 3.31
3 - you don't like how the 3.31 drives on the hills in your area

Or all 3. I'm w/ a few others, I can't follow what every you are trying to express or have a conversation about.

zx12-iowa

Agreed. I've had the 3.31 and no mas.

chimmike

meh, I disagree. experienced 3.55 in hilly areas and it's not the rear gearing. The 10sp transmission is the great equalizer. The similarities in the gearing and how it affects average rpm, especially at cruise, is so minimal it's insane.

I have 3.31s, tow with them, and drive rather aggressively. Father in law has 3.55,s and I spent about 25hrs over the course of a long weekend at the wheel of his, otherwise identical truck but with 3.55s....and noticed no difference whatsoever.

Put in tow haul or sport mode so it doesn't skip gears, and the 3.31s are just as good as any other gear.

bcb97

This issue has been discussed many times before and bogging down isn’t caused by the rear end, it’s the shift points. Both the 6R80 and 10R89 like to shift up too soon causing the engine to bog down. This is why I lock the top gear out when I am driving around town. I’ve had a 3.73 before and it bogged down just like my 3.31 does.

chimmike

agreed. gearing and numbers is not subjective. This objective physics.

the trans shift points and intended cruise rpm is too low no matter the rear gearing.

BadAV

I agree; I have no issues with my 2015 3.5 eco FX4 with 3.31s, and I am running 33" tires. I do run an 87 p/t tune, and the shift points and characteristics have also been changed as part of the tune. The low rpm torque provided by the turbos is a great equalizer, especially when towing heavy.

KubotaB

Then how can you explain one truck with 3.31 bogs down and the one with the 3.55 has not once in 2 weeks on the exact same ride. Based off what your saying, there would have to be an alternate computer program with different shift points in the 3.55?

Ryan_2020

I am pretty sure his title was supposed to be 'Purchased a 2018 3.5 Ecoboost, now I am stuck with it' lol

chimmike

the rpm difference at cruise, especially in top gear, is 100-200rpm TOPS between the 3.31 and 3.55. Both are going to bog.