Friend of mine just popped round in his fiesta ST. Took me for a spin as he was complaining of an odd sound.
Once the car gets to 50-60mph there is a loud deep sound. Almost like tyre noise but x10. Its almost enough to drown out conversation.

We tried knocking it out of gear when it was making the sound, also checked all the wheel bearings, and drive shafts etc back at mine and all appeared fine.

The only thing changed on the car recently was two new front tyres, but I didnt think it was possible for tyres to be as noisey as it is?!

Any idea's as to the culprit are welcome.