The key here is that the 19-inch wheels on the Audi Q5 S Line still have 55-profile tyres, not 45 profile or 35 profile. This means there is still a reasonable amount of tyre between the rims and the road, so they should be okay. The Mazda CX-5 Sport, that also comes on 225/55 R19s, is fine on them. It handles brilliantly for an SUV and the ride quality is still okay. The 8-speed Tiptronic of the Q5 will be traditional ZF torque converter automatic which is likely to be far more robust, reliable and predictable than a DSG or 's-Tronic'.