MONTMELO, SPAIN -- Lewis Hamilton topped the fourth day of pre-season testing as he finally notched up a decent day of mileage in the new Mercedes W09.
The freezing conditions of the first three days finally gave way to warmer temperatures on Thursday morning, but fog and drizzle left the track soaked for the start of the session.
Due to the cold weather, Hamilton had completed just 25 laps prior to Thursday but made up for lost time on a drying track in the afternoon by adding a further 69 to his total for the first test.