LPG is a classic example of a lost opportunity. Gas is alot alot alot cleaner than oil. The US has seen huge CO2 emissions reduction over recent years and it's mostly from their transition from oil to shale gas. Moving to LPG for cars would be a very beneficial interim step and relatively low cost.
Sure you dont get the same energy density from gas....Think people I knew that had dual fuel cars had an LPG tank of around 50 litre capacity, which got them about 150 - 200 miles vs 450 - 500 miles out of about 65 litres of diesel (though my old BMW M2 got about 200 miles from 65 litres) so very manageable for most people. Fill up time, which is what is really important to people, was similar to that of petrol/diesel, cost was comparable.
But I maintain the optimal initial solution for cars is sustainable fuels. We have the technology already, just needs scaling up and productionising (where the 'big bad' oil companies come in), is already being implemented in very very small and niche scales, doesn't consign current global supply chains and cars and infrastructure to the scrap heap overnight, and will provide an indefinitely sustainable transition to whatever technology wins out in the future, wether that be battery EV, hybrid, hydrogen or whatever else. Pushing for battery tech at the pace we are will cause (and is cuasing) such a CO2 debt it will take centuries to pay off once we achieve net zero and cost so much money causing such a devastating affect on our global economic growth that it will be far more harmful to human life and the environment than if we did nothing at all. It's a path that is being pushed by politicians for political reasons, not engineers and scientists charged with fixing a problem - which is what engineers and scientists do well and politicians don't do well at all.
