How do automobiles filled with catalytic converters reduce air pollution ? Suggest the best fuel for such vehicles.

Explanation

`**" "`Catalytic converters have expensive metals like platinum-palladium and rhodium as catalysts.
`**" "`As the exhaust emission passes through the catalytic converter, unburnt hydrocarbons are converted into carbon dioxide and water.
`**" "`Carbon monoxide and nitric oxides are changed to carbon dioxide and nitrogen gas respectively.
`**" "`Unleaded petrol is the best fuel.