Back in the good old days when diesel was not only cheap, but cost less than half that of gasoline - before the EPA and wacko environmentalists stepped in and did everything in their power to make it more costly, forcing engine manufactures to require cow urea to be a separate cost to make the engines run.
Yep. Government long ago purposely made the less-refined diesel more expensive.
Just like the 55mph speed limit.
Just like CAFE standards.
‘Eff em all.