RPM on HEMI with 3.21

[Pedja]

Then what will be difference in MPG between 3.21 and 3.92

 

[Rob5589]

Then what will be difference in MPG between 3.21 and 3.92

There are several threads about mpg where you can gather information. Generally, the 3.21 is a few mpg's better. But there are varying factors at play; fuel formulation, driving habits, tires, vehicle configuration, etc. Be aware, most manufacturers base mpg on the base build and that is what will be on the window sticker. But you may not see those numbers with your particular truck.

 

[Wheeler]

Then what will be difference in MPG between 3.21 and 3.92

City not much actually 3.92 does better on city roads.
Hwy almost 2 miles less than 3.21
But way more fun to drive that would compensate for MPG Loss.

 

[Willwork4truck]

Lots of angst on 3.92 mileage, some from Rebel owners... wonder why 35's and a taller, heavier truck might do that? (ok, funnin' with you Rebel owners...)
Basically if mpg's really bother you, I can probably find what dealer got stuck with my 2011 Prius and let you know where it is.

 

[J-Cooz]

My 3.92 Limited (heavy) gets 20-21mpg on the highway around 65-70mph. If you go faster the MPG drops a lot.