A number of years ago a pilot flying a C172 with 3 pax got his fuel sums a little wrong and realised that he was getting somewhat low on his return leg. He therefore slowed down to what he thought was the speed for maximum range and leaned out his engine as much as he could (2000').
If he was flying at best range than the power setting would have been in the range of 45 %.
Just to clarify a big point. Maximum range is obtained at the best combination of
groundspeed and fuelflow.
Speaking generally;
In zero wind conditions the speed for maximum range is the best lift/drag ratio speed - best glide speed.
In a tailwind it pays to reduce towards minimum drag (minimum sink speed).
In a headwind it pays to increase speed.
The best example being having a GS of 0 when at 75% power setting in level flight. In that case increasing power will increase range.
So someone stating that they got the best [B]range[/BB] from the aircraft may in some cases indicate that they were operating at a lot more than 75% power if they were at a level that is lower than that at which the engine is unable to produce more than 75% power (normally aspirated).