Recommended Project Settings

Min/Max Contact Settings

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.

Max Terminal and Angular Velocities

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

Physics Tick Settings

It is highly recommended to choose one of the options below. These options help ensure the physics run at a consistent and stable frame rate. This will dramatically decrease physics errors and allow vehicles to be stable at low frame rates.

Option 1: Substepping

Substepping divides a single game frame into multiple physics ticks. This means that physics will tick multiple times per frame to reach its target FPS. This is a great option if you want your physics to match the game's FPS in most cases but still stabilize at lower frame rates.

When using substepping, physics will always be locked to your game's FPS when it's above the target. When below the target, substepping will get as close as it can to the target FPS, utilizing the resources you allow it.

0.016667 / 6 = 60 FPS Physics @ 15/30 FPS
0.013000 / 6 = 90 FPS Physics @ 15/30/60 FPS0.009400 / 8 = 120 FPS Physics @ 15/30/60/90 FPS

Option 2: Async Physics

Async physics completely decouples physics from the FPS. Physics are calculated on a separate thread, sent back to the game thread, then interpolated for visual smoothness. If you need the best absolute consistency, this is the option to choose.
Note 1: Do not use this option in AVS 1.3 (UE5.0 - 5.1)

Note 2: Async Physics in Unreal 5.3 is broken, stick with substepping

0.033333 = 30 FPS0.016667 = 60 FPS0.011111 = 90 FPS0.008333 = 120 FPS

That should be it! The Vehicle System should internally take care of any other settings where possible.