Why 4 stroke engine is used in cars?

Answer 1

4 stroke engine is used in cars to give them more power.

Or

The four stroke system does not have to have oil mixed in with the fuel, because the sump can be used for storage and pumped around galleries.

Two stroke engines are less convenient and also cause pollution, due to the unburnt oil causing smoke.

Some eastern block cars used to have 2 stroke engines, like the Trabant and Wartburg.