Touring Cars- tune or not tune is the question

[Smoothherb]

So I am a fan of the DTM Cars. I have collected many of them and my question is: What is a realistic setting for this cars?
Full tuned or stock? Sport tires or race tires?
Thanks allot

 

[Sandy106]

Stock on race tires is probably the most realistic. They usually put out ~500 HP in real life, fully tuned on GT5 they can hit 700 HP or more.