F250 3.73 to 4.30 axle ratio

I agree, it makes every gear more efficient as you put it, but that really only matters when you talk about first gear because you can’t choose a more efficient gear. So if 8th gear is not efficient enough, you could just downshift to 7th. So with 3.73 gears 8th may not be efficient enough, but 7th will be. With 4.30 gears 8th May be efficient enough.

Now why the ratings are different with different gears I don’t know.

All that being said, my next truck will probably have 4.30 gears and a 10 speed.