Hello, I ride on my A4 3.0 TDI Quattro has the following tyres: Michelin Alpin A5 (Winter) Conti Sport Contact 5 (Summer) Both have now 30 tkm down and I have saw tooth formation (beginnings) on both tire sets. You can feel and hear it. Saw tooth formation after 30 tkm is unacceptable in my view. The following applies to : 1. Track & fall are correct 2. With prescribed tire pressure driven 3. Do not run overloaded 4. Ride about 30 tkm a year long distance. My questions: 1. Si nd Quattro driven vehicles susceptible to this ? 2. How can I prevent this ? 3. Which tire does not do this ? I hope you can help, because this noise is very annoying and I do not want to have to buy all 30 tkm new tires. Hope you can help..