Ideal cruising RPM for MP8?

Volvo D13/Mack MP8 also falls flat on it's face over 1750!
Just sayin'..........

JD

 

True.......it's not going to come apart. But all the motor is doing up that high is making a lot of noise and less power!

JD

 

I felt the same. We were pulling 100k frac pumps around pa/wv with 445 and 505hp. I was pretty impressed at the low rpm grunt. The ISX 12 liked a few more rpms

 

I drove a Mack with the MP8 505/1860 with iShift 12spd. 3.25 rears it was turning 1750rpm roughly 82-83mph. It came with lo pro 22.5s but had 11r22.5s at the time and the speedometer wasn’t recalibrated. I could get low 5’s MPG running 75ish. Obviously iShift a bit different gearing but for the “suggested” RPM on those motors it was a bit high. It ran and pulled like a scalded dog though lol

 

For what it’s worth the Volvo I have now (D13 same engine) has 3.08s with the ishift, set at 455/1850 and I only get high 5’s/low 6’s with it. We usually run heavy and I idle every night though.

 

Your driving way to fast.
Spend a week never going above 65 and I bet your mileage hits 6 mpg.

 

You can't be making to much money ?
What is your cost per mile for fuel ?
You have got to be what .50 - .60 cents per mile on your fuel cost ?

 

Your also running tall tires so that will lower your fuel mileage.