Effects of Under-inflation:

1) Uneven tread wear, more wear at tyre sides.

2) Lack of directional stability.

3) Increased rolling resistance leading to increased fuel consumption.

4) Excessive flexing of sidewall causes build up.

5) Vehicle will roll on curves.

Effects of Over-inflation:

1) Reduced tread contact area with road surface.

2) Reduced tyre grip.

3) Increased vibration resulting in uncomfortable ride.

4) Increased stresses may causes tread separation and crack in the side wall.

5) The centre of tyre will be worn rapidly.