Originally Posted By: Hokiefyd
Mechanical efficiency and fuel consumption are different things. It's fascinating to look at Brake Specific Fuel Consumption curves for different engines. This measures fuel consumption per work done (power output). Essentially, it measures how efficient an engine is at producing torque. Look at the torque peak; not the horsepower peak.
The lowest BSFC occurs at near full throttle in the 1500-3500 rpm range. That doesn't mean that that's where the lowest fuel consumption is. However, you CAN see that the engine is much less efficient at producing torque at lower engine speeds and at lower engine output (the lower left of the graph).
Engines are usually most efficient at producing torque near their maximum rated load.
http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption
Thank you for the explanation.
Badtlc - "Mechanical efficiency and fuel consumption are different things." My experience with fuel consumption is fact. Regardless of how or why. Therefore, I AM "familiar with that of which I speak." You then chimed in with mechanical efficiency, which I don't know much about, and never claimed to. You were correct there. But these are "different things."
2+2=4.
2x2=4.
Both are correct, yet different. I know addition, you know multiplication. Both yield the same result.
I guess I don't understand how this thread got so technical.
Mechanical efficiency and fuel consumption are different things. It's fascinating to look at Brake Specific Fuel Consumption curves for different engines. This measures fuel consumption per work done (power output). Essentially, it measures how efficient an engine is at producing torque. Look at the torque peak; not the horsepower peak.
The lowest BSFC occurs at near full throttle in the 1500-3500 rpm range. That doesn't mean that that's where the lowest fuel consumption is. However, you CAN see that the engine is much less efficient at producing torque at lower engine speeds and at lower engine output (the lower left of the graph).
Engines are usually most efficient at producing torque near their maximum rated load.
http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption
Thank you for the explanation.
Badtlc - "Mechanical efficiency and fuel consumption are different things." My experience with fuel consumption is fact. Regardless of how or why. Therefore, I AM "familiar with that of which I speak." You then chimed in with mechanical efficiency, which I don't know much about, and never claimed to. You were correct there. But these are "different things."
2+2=4.
2x2=4.
Both are correct, yet different. I know addition, you know multiplication. Both yield the same result.
I guess I don't understand how this thread got so technical.