The sound is purely speed-dependent, and becomes audible from about 50 km/h, it is a “rrrrrrrrrrr”… which, when the speed increases, logically also increases the pitch/frequency. It does NOT change in the case of load changes, NOT in the case of curves, NOT in the case of brake actuation, also not analog to the speed, but it rolls somehow with… purely speed-dependent, no matter which gear I am in. noisey what only “freaks” hear, but it’s also not really loud, but every passenger asks at some point “what’s that for noise?” It sounds like a plastic fan, not directly a hum, rather such a “plastic noise”, a bit like when you walk with the fingernail on a PC fan. It’s not a plastic part that scrubs on the tire profile, because I have already “driven” the car on the lifting platform – without wheels, even then the noise is there. Unfortunately, I can hear this It’s just perfect to hear it inside (from 60 km/h), when you have closed all the windows. I ALWAYS drive in summer with an open sunroof (noise level) and didn’t notice it until autumn, when I had closed everything. So I can’t tell if it came slowly or suddenly appeared. I’ve been driving about 2000 km since then and I think that the noise hasn’t worsened or only slightly since then. f a little something that I can discover and fix during the seasonal bike change, but Pustekuchen…., I don’t hope for anything in the differential? Or can a wheel bearing sound like this, especially without load and wheel on the lifting platform? A wheel bearing is rather buzzing and changes in load (curves), isn’t it? STS (Bj. 05/01, EZ 12/02) has 95,000 km on the clock. Wheels are a bit wider than series, with distance discs, which of course puts a little more strain on the wheel bearings. Gear oil is approx. 2 2,000 km old. There’s no missing… About Tips/Ideas I would be very grateful to you!