RoyJ wrote:
Shiner, as far as I can tell, BFSC is proportional to thermal efficiency.
An IC engine turns fuel into 3 components: mechanical power, exhaust, and radiator heat rejection. Both of the latter is wasted heat (I know, some is captured by the exhaust turbine, even more so if it's a compound turbo like Detroit DD15).
Since BSFC = fuel consumption / power. Therefore the better the BSFC, then the better mechanical power to wasted heat ratio. Thus the higher thermal efficiency.
So I believe we can safely state: the better the BSFC, the closer an engine is to max thermal efficiency.
You are correct. I agree.
