Do Mesh Normals Influence Physics Behavior

I created a raycast vehicle arcade simulation and used for the initial development the Unity Terrain Engine. On the Unity Terrain my physics are absolutely smooth but the terrain setup appears to cost intensive for the mobile platform. I converted the terrain with T4M to a static mesh object. Now my raycast vehicle is often behaving odd. My guess is that the problem is caused by the rougher edge transitions of the low poly mesh. I can also clearly see that this unwanted behavior is getting less with denser meshes.

Can smoothed normals influence the behavior of physics on a low poly terrain or is just a thing that makes an object look round/flat shaded? What other options do I have?

Peter.