No Reserve (Best Economy Range)
The words in brackets are familiar to me; I think they appear in the Lyco documentation.
They refer to operation at peak EGT. This is authorised, in general, at 75% or lower power settings.
Now, how many people know how to lean to this power setting? How many have the instrumentation to do it accurately? How many can even do it without excessive vibration?
If you fly "UK PPL training style" i.e. full rich, the fuel flow is going to be about 30% higher.