Hi! Last year I bought a set of summer tires Michelin Pilot Sport 4 245/40 ZR18 93 Y AO for my S4. At some point you got the opportunity to re-examine the Vmax on the track. Normally the car runs at max. turnzal approx. 318kmh. And until then I had always raised Pirelli because they just went great and had a good grip. However, I had to change because the last set turned the vehicle into a vibrator, which sic The tires are absolutely in the norm. So now Michelin. And here the Kathastrope: from 270kmh it started to whistle, really loud. Several times tried. And as soon as I got even faster, the car started to swim like at Aquaplaning. So very scared again slowly. Pipe away. Gas: from 270kmh whistle, from 280kmh still louder whistle and then drive like slit shoe! The hammer. The tires have AO un un d are approved for 300kmh. The Pirellis had no AO and they stayed on the ground at over 300kmh as well as at 180kmh. So if someone has a corresponding vehicle that has no Vmax limit: fingers away from Michelin! Normally with limited Vmax that does not notice. And up to this speed they also run great and have felt more grip than the Pirellis. Nice Sunday! HJ