Why does my car whine at high speed?

Most often worn wheel bearings, less commonly a tyre with feathered wear, a worn diff (rear-wheel drive), or transmission fluid issues.

Here's a quick, honest answer from a working UK mechanic — what causes it, what it costs to fix, and what to do next.

Is a whining wheel bearing dangerous? — If left for months it can seize. Replace within a few weeks of noticing the noise.

Will it fail the MOT? — A wheel bearing with excessive play fails the MOT.

Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email bob@bobsmechanicalrepairs.co.uk.