How To Easily Port BP Code Between Vehicle Versions?

OK Unreal Engine will warn me about obsolete nodes when I open my project in a newer engine version, let’s say from 4.16 to 4.19 for the sake of discussion and clarity.
I don’t understand: my 4.16 vehicle migrated to 4.19 and opened in UE 4.19 will continue to behave like a 4.16 vehicle? I mean if there are physics handling improvements in 4.19 my vehicle will get them or it will still be handled by the physics engine like a 4.16 vehicle?
Thanks but I just can’t figure this out.