system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are there so many clean air natural gas buses but not many natural gas cars?
gpt
One major reason is that CNG (*Compressed* Natural Gas) requires a pressurized container and contains less energy per volume than gasoline at any reasonable pressure. Thus the fuel tank takes up much more space and mass, which is obviously less of a problem in a bus. It also makes distributing the fuel slightly harder, which favors centralized locations like bus depots.

Then there's the simple thing that 'everyone' uses gasoline anyway so most new development is still focused on it.