Forum Discussion
Jim_Norman
Apr 22, 2017Explorer
A) define Optimum Speed? Are we talking MPG, Comfort driving, or how long it takes to get there?
If MPG, you will need to look at the torque curve and shift points of your engine/trans combo. Usually this will fall around the 59-64 MPH mark. As an example I THOUGHT 62 was mine, learned that my Cummins likes 64 better or more tot he point regardless of MPH it likes 1750RPMs so if I am doing 64 in 6th that is about right, but if I have to slow don, then 5th gear can actually give better mpg at higher revs than 6ht at lower.
If you are nervous driving at 65 but more comfortable personally at 55, then 55 is your speed, just make sure you try to stay out of the left lanes in higher speed areas.
Lastly if it is how long till we get there, then 5 over where it is safe to do so, but be extremely cautious on curves, down grades and with braking distances.
If MPG, you will need to look at the torque curve and shift points of your engine/trans combo. Usually this will fall around the 59-64 MPH mark. As an example I THOUGHT 62 was mine, learned that my Cummins likes 64 better or more tot he point regardless of MPH it likes 1750RPMs so if I am doing 64 in 6th that is about right, but if I have to slow don, then 5th gear can actually give better mpg at higher revs than 6ht at lower.
If you are nervous driving at 65 but more comfortable personally at 55, then 55 is your speed, just make sure you try to stay out of the left lanes in higher speed areas.
Lastly if it is how long till we get there, then 5 over where it is safe to do so, but be extremely cautious on curves, down grades and with braking distances.
About Motorhome Group
38,761 PostsLatest Activity: Nov 16, 2025