What is the ford focus rs lug nut size?

The Ford Focus RS lug nuts are M12 X1.50 with a 19mm hex. This means that in order to remove or install Your lug nuts You will need to use a 19mm socket. When You need to remove lug nuts from Your car it is a good idea to use an impact driver. These can break the torque easily on a lug nut and that makes them much easier to remove. When reinstalling lugs You should only use a calibrated torque wrench. Using an impact driver to put lugs on can over torque them That can strip the wheel studs or the lug nuts out and then You would need to replace them to get them working again.