Ok, update time: The game update #3 didnt solve this issue and its pretty much constatnt now I decided to do some more fault finding: the gra[hcis card driver has been update to the latest one from Nvidia and I m using the auto-detect setting from the Nvidia GForce experience panel so everything is pretty much set at mid level graphcis for the sim. I also completely clearing out my community folder jsut incase anything was causing conflicts…no luck, still the judder every 2 or 3 seconds. I’ve just put the sim in developer mode and opened up the FPS/Graphics performance panel and it looks like something is causing the GPU performance to dip every 2 or three seconds, Its doing this at all times when the game is running, eg here is the map screen: