In what respect is fuel oil better than coal?

Combustible fuels

1. A fuel that is burned by mixing with air is known as combustible fuel.
2. Oil and coal are both combustible because they react with air and generate heat energy.

Fuel oil is better than coal

1. Oil during burning emits less carbon dioxide while coal release in big amount.
2. Oil does not produce ash after burning whereas coal produces a big chunk of ash.
3. The oil does not produce smoke while burning, while coal produces lots of smoke which contaminates the environment.

Hence, the fuel oil is better than coal.