It is different in different countries
We ran a 100% LPG fleet and where possible popped LPG for lift engines in the vans
They actually got better MPG on LPG than the petrol engines did at speeds under 80 kph.
And we are talking around 1/4 the fuel cost.
There was a battery conversion available that used spiral cell Pb batteries and gave a range of around 150 km we looked at doing this and it was a close call as the payback was around 3 years.
We did try air start using a brake operated air compressor
That dropped the fuel consumption by around 15% because the electricity used to start 60 times a day has to come from the engine.
They worked well but took way too much maintenance so we only ever fitted two of them and were glad to pension those vans off.
What saved a lot of money was to change the door locks so the loading section was on a different key then installing a burgular alarm that cut off the engine if the door was opened other than by the alarm deactivating.
As they were all LPG they could sit in docks for extended periods with the engine running and as most of our work was street parking they could sit all day without turning the engine off.
Drivers liked this because they could leave the air con / heater on all day.
The people who will convert to EV's in a flash are the large delivery fleet owners
One to 2 tanks of fuel a day, oil changes every month, full services every 2 to 3 months the costs become astronomical in a very short time
Our biggest variable cost was wages .
Fuel was a close second and full vehicle running costs were about 70% of the labour costs .
Ask a taxi cab owner about their running costs
IN Sydney the average private owner does 15,000 km a year
The average delivery vehicle does that 15,000 km in 1 to 2 months
I would hate to think what a mail collection / delivery van does in a year
Aust Post is switching to E-bikes & E-Quads for outer urban mail deliveries and that is expected to save around $ 1,500,000 / year in operating costs and have a break even in 9 months.