CNG/LNG and propane are widely used overseas in cars and even large diesel trucks. Over 90% of cabs in Bangkok run on it and the city is larger and has more cabs than Ny.They tell me it pops fine in compression ignition trucks. Of course almost 100% of equipment like forklifts that are used indoors use propane as burns total clean.As I travel alot I noticed even motorcycles in China use it.
Perhaps natural gas vehicles should have been pushed instead of the failing electric ones no one buys. We could have been energy independent by now.