Britain's Alexander Sims headed the first of two days of Formula 3 European Championship testing at Hockenheim.
Seven hours of track time were scheduled, but the day took place mainly in cold-and-wet conditions. The circuit dried out during the afternoon so that there was just over one hour of dry running.
Sven Muller, who had just one rain-affected private test under his belt since switching to Van Amersfoort Racing, moved to the top of the times for approximately 20 minutes. He was then knocked off the top spot by Ferrari protege Raffaele Marciello, before Sims moved in front with T-Sport's ThreeBond/Nissan-powered Dallara.
Behind McLaren GT works driver Sims, who only joined the European F3 field in July, championship leader Marciello ended the day second in his Prema Powerteam Dallara-Mercedes, with Muller third.
Jordan King, who shone at Hockenheim's round earlier this season, was close at hand in fourth place with his Carlin machine, while Felix Serralles and Lucas Auer completed the top six, just ahead of single-seater rookie Jann Mardenborough.
Marciello's title rival Felix Rosenqvist finished the day in 16th place.
Two of Rosenqvist's fellow Swedes joined the field at this test. John Bryant-Meisner warmed up for his forthcoming series debut with Fortec by taking 13th place, while GP3 regular Jimmy Eriksson, who has taken over Muller's vacant Ma-Con car for the week, ended up in 22nd.
Pos Driver Team/Car Time Gap
1. Alexander Sims T-Sport Dallara-Nissan 1m33.872s
2. Raffaele Marciello Prema Dallara-Merc 1m33.980s +0.108s
3. Sven Muller Van Amersfoort Dallara-VW 1m33.998s +0.126s
4. Jordan King Carlin Dallara-VW 1m34.037s +0.165s
5. Felix Serralles Fortec Dallara-Merc 1m34.219s +0.347s
6. Lucas Auer Prema Dallara-Merc 1m34.235s +0.363s
7. Jann Mardenborough Carlin Dallara-VW 1m34.243s +0.371s
8. Dennis van de Laar Van Amersfoort Dallara-VW 1m34.263s +0.391s
9. Nicholas Latifi Carlin Dallara-VW 1m34.294s +0.422s
10. Eddie Cheever Prema Dallara-Merc 1m34.354s +0.482s
11. Daniil Kvyat Carlin Dallara-VW 1m34.393s +0.521s
12. Alex Lynn Prema Dallara-Merc 1m34.471s +0.599s
13. John Bryant-Meisner Fortec Dallara-Merc 1m34.522s +0.650s
14. Harry Tincknell Carlin Dallara-VW 1m34.560s +0.688s
15. Mitchell Gilbert Mucke Dallara-Merc 1m34.672s +0.800s
16. Felix Rosenqvist Mucke Dallara-Merc 1m34.707s +0.835s
17. Tom Blomqvist EuroInternational Dallara-Merc1m34.729s +0.857s
18. Andre Rudersdorf Ma-Con Dallara-VW 1m34.743s +0.871s
19. Roy Nissany Mucke Dallara-Merc 1m34.931s +1.059s
20. Antonio Giovinazzi Double R Dallara-Merc 1m35.095s +1.223s
21. Michael Lewis Mucke Dallara-Merc 1m35.296s +1.424s
22. Jimmy Eriksson Ma-Con Dallara-VW 1m35.308s +1.436s
23. Spike Goddard T-Sport Dallara-Nissan 1m35.327s +1.455s
24. Tatiana Calderon Double R Dallara-Merc 1m35.541s +1.669s
25. Sean Gelael Double R Dallara-Merc 1m35.768s +1.896s
26. Sandro Zeller Jo Zeller Dallara-Merc 1m36.054s +2.182s
27. Michela Cerruti Romeo Ferraris Dallara-Merc 1m37.831s +3.959s