Rosberg actually doing something smart though. In 99% of situations with 1-2 assured in this situation the team tells the drivers to turn the engine down several modes and cruise to the end. If both drivers do it the lead can feel safe in doing so. Hamilton however is on his 4th turbo, Rosberg isn't, he knows that. It's in Rosberg's best interest to keep pushing fastest laps to get Hamilton to keep his engine turned up and doing fast laps. The more wear on Hamilton's engine the better as far as Rosberg is concerned now.