Compressed Air Engine

This idea has been around for a long time - there used to be "fireless" compressed-air locomotives for use in mines or plants where inflammable or explosive materials were used. They had a compressed air tank driving a reciprocating engine. Also the French inventor Mekarski developed a compressed air engine for tramcars (streetcars) which was used in Nantes for 31 years from 1880, after which electric traction was used.

I don't know about energy efficiency -The idea was tried on the Wantage Tramway in England, but was abandoned when they found the air compresing plant used 4 times as much coal as a steam locomotive. Electric traction would use even less coal than a steam loco.

I would think the weight of the tank would be a problem for a smaller vehicle such as a car, but I guess the Indians have got around that. In a short range city car that may not be such a problem.