Nico Rosberg and Lewis Hamilton had the fastest laps as Mercedes dominated the first practice for the German Grand Prix on Friday.
Rosberg's best time on the Hockenheimring track was 1 minute, 19.131 seconds, beating teammate Hamilton by 0.065.
Ferrari's Fernando Alonso was third, trailing Hamilton by 0.227, followed by Daniel Ricciardo, Jensen Button and Sebastian Vettel.
Kimi Raikkonen was beset with water pump problems early on, but Ferrari fixed the problem and the Finn emerged to set the eighth fastest time behind McLaren's Kevin Magnussen.
Turns 1 and 8 proved the most problematic on a morning of minor errors.
Rosberg leads Hamilton by just four points going into Sunday's race at the halfway stage of the season.