“””Diesel prices raced ahead on unleaded prices several years back when the government mandated low-sulfur formulations. That, and the requirement for diesel exhaust fluid and the poor performance of government-mandated pollution controls has made what was an affordable, reliable system too expensive and too maintenance-intensive to be of any real value.”””
You are correct. I will also add that gasoline and diesel prices are a supply and demand issue.
For gasoline—— electric vehicles and converting corn to ethanol have created an over supply of gasoline.
For diesel—— the banning of heavy fuels on ocean going vessels has increased the demand for diesel.
I still have my Mercedes diesel car and I remember the days before the above events and diesel was lower priced than gasoline.
That was a long time ago! We had a couple old Mercedes diesels in the family from the 60s until the early 90s (when they finally died). Diesel used to cost $0.25/gal when gas was $0.35/gal.
The oldest one was fun to drive on the freeway. No-one would ever tailgate you for more than a few seconds because of the smell of the exhaust, and it would occasionally "roll coal" all by itself, too, so some people would get a large dose of black, oily smoke. It did get 40 mpg on the highway, which was impressive for a large sedan, but it only had 60 hp.