Hamilton puts racy initials on US GP helmet

Hot on the heels of the FIA’s warning about foul language, Lewis Hamilton has featured an obscene acronym on his helmet for the US grand prix.

Bild newspaper said the prominent decal on the back of the departing McLaren driver’s helmet in Austin is "H.A.M."

"The initials do not stand for his last name, but for ’Hard as a motherf***er’," the German newspaper claims.

Hamilton’s 2013 boss Norbert Haug grinned: "Lewis is just saying ’Hard as Mercedes!’"