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Please do. It will save an awful lot of fruitless questions and answers, which could easily send everyone on wild goose chases. I am reminded of the old joke about the motorist who complained of the whining from the back of the car and was told to cure it by leaving the mother-in-law at home.

You need to stick to something with the same overall parameters. So to have a higher sidewall, you'll need to reduce the wheel size down from 21". This website shows the options: https://www.wheel-size.com/size/audi/a7/2013/ In summary, the options are: 255/45ZR18 99Y 8.5Jx18 ET32 5x112 2.4 / 2.1 235/55R17 99H 7Jx17 ET25 5x112 2.4 / 2.1 235/55ZR17 99Y 8Jx17 ET30 5x112 2.4 / 2.1 235/45R19 99V 8Jx19 ET26 5x112 2.4 / 2.2 255/40ZR19 100Y 8.5Jx19 ET32 5x112 2.4 / 2.2 255/40ZR19 100Y 9Jx19 ET32 5x112 2.4 / 2.2 265/35ZR20 99Y 9Jx20 ET37 5x112 2.4 / 2.2 275/30ZR21 98Y 9Jx21 ET35 5x112 2.6 / 2.3 My only query would be whether a smaller radius will fit over the brakes, but from your picture the brakes look normal sized so you should be able to drop all the way to the R17