My personal experience includes several years of working for Chrysler as an emissions control engineer. We routinely swapped axles and noted the results of same. Even with SI engines, we never achieved a reduction in fuel economy equivalent to the axle ratio change.

You've got a patronizing attitude with some poor anecdotal evidence and no data. You cannot even get your own data accurate within a couple of percentage points. By your own admission, you've rounded your data to a convenient 20%. This is simply BS.

I've got an engineering degree, several years of hard data from an automobile manufacturer, personal experience, and the knowledge of diesel engine theory.

We'll let the forum decide who to believe.