It is customary to state power and torque at their highest value, 'maximum' power or 'maximum' torque. That means that the fueling is also at maximum or wide-open-throttle.
I suspect that biodiesel makes more power than petrodiesel (at less than peak power rpm) due to its slower burn rate. It's conjecture on my part, but I could believe that a longer duration burn can keep cylinder pressure higher than a quicker flash. At higher rpm the piston can be pulled down faster than the biodiesel burn rate can create expansion and so there is less cylinder pressure, less power (and a lower maximum rpm, too).
The power vs. fuel volume difference isn't changed because of D2 or B100. The fuel pump command has no means of knowing the fuel type. The pump displacement isn't changed, it's still some same percentage of stroke limit regardless of fuel.
There is no need to adjust the fuel ratio when a diesel's air flow is unthrottled and therefore unregulated.
My best fuel economy tests have been on B100, mainly because I only use B100 in fuel economy competitions. That's not because B100 provides better fuel economy, but because the use of B100 does not cause a loss of fuel economy in real world driving in real cars on real roads.
The BTU values are often calculated at condensing temperatures. None of our cars run with the exhaust that cold. We aren't getting, we CAN'T get, all the BTU energy out of diesel or bio (or gasoline either) in automobile engines.
The energy that CAN be used for motive power is equal with bio or petroleum diesel, it's just that there is less wasted latent heat out the tailpipe with bio.
