1.8 Zetec transmission noise

Is there anything obviously different between the two front tyres as regards wear or tread pattern?

Does one wheel get hotter than the other after a lengthy run to indicate that something is dragging?

The other thought is that it is in the area ahead of the O/S Front wheel and when the wheel is thus turned to the right it isn't in the way to mute the sound. Could part of the undertray be partially lose and acting like the reed in a wind instrument and virating

There's no real diference in the tread pattern or wear, but I thought it was worth swapping the front tyres to the back just in case. Did the drivers side (swapped the front for the spare, swapped the back for the front, swapped the spare for the back)started jacking up the passenger side and the bl***dy jack failed just as the car front endlifted off the ground (the thread pulled through). Anyway, after recovering from the shock with only one side changed I took the car out for a spin again and it's made no difference at all. SupposeI will have to get another jack and do the passenger side still before i put it back in to a Ford dealer. Just as well it failed when it did because it would have not been much fun if it had let go when the wheel was off eh?