Lewis Hamilton of Mercedes wins American Grand Prix in Austin , Texas . British driver held off teammate Nico Rosberg to extend his lead . Just 18 cars instead of full 22 took part in qualifying due financial difficulties at Caterham and Marussia .
Lewis Hamilton of Mercedes wins U.S. Grand Prix in Austin , Texas . British driver held off teammate Nico Rosberg to extend championship lead . Just 18 cars instead of full 22 took part in race due financial difficulties at Caterham and Marussia .