Quote:
Originally Posted by MetroMPG
Another shortcoming of the calculator is that it doesn't take brake specific fuel consumption (BSFC) into account. |
Sure it does. Engine efficiency = BSFC. A gas engine operating at ~100% efficiency would use ~80+g/kWh, so if an engine is at ~300g/kWh it's at ~27-28% efficiency. The 2nd gen Prius at a minimum of 220-230g/kWh would be at ~37% in terms of peak efficiency, which is coincidentally (not really) what
it's at. Toss in ~90-95% transmission efficiency for a locked-up auto or a manual transmission and bob's your uncle. I think it could diverge the most for an automatic trans that's always unlocked, but those aren't very common. Also the actual gasoline weight/energy content could throw things off since there's no standard for a BSFC test AFAIK.