Where I grew up in KS in the ‘80s, many farmers powered their work trucks with propane. They had huge tanks in the bed, and remote valve controls mounted under the dashboard to select between gasoline and propane sources.
There was a definite power difference between the two fuel sources, with propane falling significantly short of the power from gasoline. However, it was much more economical to run on propane day to day.
I always hated the smell of the propane exhaust, but imagine it would generate a serious feeling of nostalgia these days.