Different engine parts and a bit different suspension. I can maybe get a high 56.2 but I'm happy with this.
https://store.playstation.com/#!/tid=CUSA24769_00
...
https://www.youtube.com/watch?v=WMauznZlNPw
Polyphony Digital and Sony just seem to be ignoring GT Sport now in the GT7 advertising.
Link to the GT Sport "5 Gum" ad https://m.youtube.com/watch?v=LnJtRYZ9-ZA