Ok the truck:-
06 3500 srw mega cab, auto, 20in wheels, mild lift,(3 inch I think)
What would be the ideal highway cruising rpm...? For mileage purposes....
Any ideas will help
Thanx

 

Right around 1800...I get my best mileages under 2k RPM.

 

And what should I expect the mpg to be......?

 

Agreed between 18-2k rpm.
In my sig truck I'm getting a constant 18.8-19.2 MPG hand calc.
Don't believe the lie-o-meter.

 

I'm only getting about 14mpg, but my driving lately has been all stop and go with no highway time. I've also been told that winter blend fuel will hurt my fuel consumption.

 

Winter fuel for sure hurts and winter weather in general as well since these motors are effecient when they are hot and steady temp. Doesnt happen in winter ie takes longer to get up to temp and is harder to keep that temp maintained.

 

^^^ i agree, i get about 2-3mpg less in the winter

 

In my stock 06 the best RPM's for the best fuel mileage is 1500-1600 RPM's, with summer fuel I can get 20+ mpg (hand calculated) my mpg drop's back to 18 mpg at 70 MPG/2000 RPM's

 

1700 -1800

 

With my stock truck from 60 63 pulling my trailor is the best milage 70 75 9MPG