V6 Tdi

Hello I would like to buy a Passat Variant V6 TDI soon. And now my question: Is this motor highway fixed, so I mean it runs without problems 200 KM/H and does the engine withstand this too??? The car is not tormented by me or something, but on the highway if it is warm, it would have to run already. Also I am one of the after longer highway rides not immediately shut down the engine but let it run a little bit. One hears so much about head gasket, VTG Turbo And so on. If you should go to the TDI at all or better to the CDI, you can hear less of it. so I think. But I would rather stay with VAG. Has any of you had experiences, also in terms of consumption when driving on the highway and you should rather take the 3BG or 3B Passat. Does someone know where the V6 turns at 200 KM/H. What should I pay attention to when buying V6 TDI? I am grateful for every advice. With best thanks in advance.