...not discussing the display, rather than the arbitrary number of .66 when it's .7. It's not much, but it's neglecting 1.3f per minute.
For whatever reason i remembered a different base income for other factions. It's actually a flat +4 for all factions (no reduction for OKW), and the reduction only applies to any further fuel income.
You're absolutely right, with a good point.
But... anyways, hope you still understand / appreciate my general argumentation in this regard, and what i tried to explain.
(
...This is how OKW is intended to be played: good tech building with a fancy feature, rather cheap tech, but costly vehicles in the long run. )
Let's just use your example of ~70%, so T3 is ~115 fuel, and a Panther is around ~250, which still has the same outcome of (rather) cheap tech with pricy vehicles in the long run - my actual point, the faction design.