I saw .99 for diesel and was excited until they told me that factored to roughly 3.50 per gallon plus the conversion rate.
I believe that was the Liter price in Eurocent for Bio-Diesel - which raises up next year because government needs mor tax.
Just now normal gas is around 1.22 Euro/Liter and Diesel about 10 to 15 Cent less.
My Tribute V6 has a sequential digital injection system for Propane (here we love mixtures with 40% Propane/60% Buthane, because in summer that provides more mileage and smoother engine sound) than standard propane what ist 95P/5B - alike the bottled propane.
That systems starts on gasoline and switches over after a defined time and engine temperature (mine at 30° Celsius). If the engine is warm, it switches over within 0.5 seconds.
Propane for Diesel engines i don't have heard about in Germany - but some public transports use that and Methan, too for their busses.