The design I saw years ago (1970s) used high pressure air over hydraulic reservoirs and variable displacement pumps and motors. They were getting 40 mpg on a VW sized car. It had good acceleration with regenerative braking. They used a 20 hp gas motor but had about 100 hp impulse air/hydraulic power.
The design I saw years ago (1970s) used high pressure air over hydraulic reservoirs and variable displacement pumps and motors. They were getting 40 mpg on a VW sized car. It had good acceleration with regenerative braking. They used a 20 hp gas motor but had about 100 hp impulse air/hydraulic power.