[encantotom]

i thought it would be an interesting thread to provide data on what speed provides the best fuel economy for different engines used in our newells

i will start with some speculation on my series 60. i have read that the optimum rpm for best efficiency is 1400 on a 12.7L series 60.

i had taken a few pictures of my vmspc while driving so had a couple of data point.

70mph was 1566 RPM on a snapshot i had taken. from another one it was ~ 11 RPM per MPH in 6th gear.

so to hit 1400 RPM i would need to be at ~55 MPH.

i tend to drive in the mid 60's typically. i heard somewhere else that MPG goes up about 1 MPG for every 10mph you slow down if you are driving 55-75mph. i got about 7.4mpg on my 4300 mile trip. lots of long grades and hills on it and pulling a car.

any other data on this and for other engines as well? i know on my 8v92 i seemed to get about 6.5mpg no matter what i did...

discussion?

tom