It is not required, but highly recommended to set your Physics Contact Offset settings as low as Unreal will allow you. 

The default settings will cause your wheels to bounce when moving between separate surfaces as if it hit a bump, even when they are at the exact same height. This effect gets worse the higher your movement speed.

These settings will limit the max speed of your vehicles. I recommend these values:

• Default Terminal Velocity: 7600

• Max Angular Velocity: 10000

Highly recommended, turn on physics substepping. This setting adds extra physics frames if your frame rate drops too low, keeping the physics simulation stable.