[delbel]

there's an extremely efficient diesel engine called the Lister CS that became popular in the 1920s. It's claim to fame is that it can run 30-45 years without major maintenance and produce 1kwH per .125 gallons of diesel. That's 8kwh per gallon. It was banned in 2009 by the Obama administration because it was considered fuel inefficient by bureaucrats who didn't understand the design. There was a movement to try and de-list it from the ban. My dream has been trying to find one and draft it into freecad so people could 3d print cast iron molds and re-manufacture them. https://youtu.be/NhAD8D3sM2A?t=98

[FlyMoreRockets]

From what I can tell, the Lister was banned because of carbon particulate emissions, not due to efficiency. However, very slow turning engines like the Lister tend to have a more complete combustion and lower emissions.

[felipemnoa]

>>can run 30-45 years without major maintenance

I think it would be better to list the number of miles it can run before maintenance is needed. Just stating the time does not provide a complete picture.