As the car gets older, will its engine's compression ratio change, if yes how.

yes

Explanation:

yes, it is correct as car gets older the engine's compression ratio changes.

compression ratio is the volume in maximum compression chamber to the volume in the piston at full compression.

More and more engine will be used if the ring wears compression goes down

or there can be one condition if carbon build up on the piston then this can alter the compression ratio.