There is a paper by Artur Bensel from Hamburg University at
this site which disputes the old academic derivation of best range speed still air of 1.316 VMD (which relies on the assumption that TSFC is constant) and suggests 1.09 VMD is more likely (actually 1.05 to 1.11), hence possibly giving managed speeds closer to GD than you would expect from distant ATPL studies...and slower still in a tailwind