We calculated distance with our calculator and with the help of International map agencies and distance between Stuttgart Airport STR and Marienplatz Stuttgart is 120 km.
If you go from Stuttgart Airport STR to Marienplatz Stuttgart, with normal traffic conditions and non-stop driving, you reach final destination in 1,5 hours.
Depend on car conditions and fuel quality, to travel from Stuttgart Airport STR to Marienplatz Stuttgart with car transport, you need 7 gallons gallons of petrol, which will cost around 10 $ with average prices.