Quote (FMX_89 @ Apr 10 2014 02:04pm)
Your variable load statement works both ways. What I was referring to as untrue was your statement that lower engine RPM=better economy. That is not always true, and you said it yourself.
Peak fuel economy for my diesel is 1400-1800rpm. It will easily roll down the road at 1200rpm without hesitation. Lower RPM, fuel economy is worse. It's possible. All I was saying. Anyone that has owned a 4cyl/5 speed ranger can attest to that.
What is your MPH difference between 1400-1800rpm vs. a slower 1200rpm? Is your diesel an auto or manual? I guess a noticeable difference could happen if a larger diesel and a manual tranny....getting back to the "bogging" area of power band. I'm surprised a little 4cyl would have that much difference.
Making a general statement here and not speaking about the specific powerband area of the engine = Instead of being close to the redline (high rpms) a lower RPM will save more gas.
Pretty much goes back to my original statement of slow down. My general statement is not taking into consideration specific powerbands of engines to be at their most efficient.