Nico Rosberg beat his Mercedes teammate Lewis Hamilton in Friday’s first practice session for the Russian Grand Prix, while Red Bull tested a new canopy to protect drivers from flying objects on the track.
Ahead of Saturday’s qualifying, the first practice underlined the dominance of the Mercedes team, which has been on pole for 39 of the last 41 races.
Rosberg, who has won all three races this season and is 36 points ahead of Hamilton overall, led him by .722 seconds.
Ferrari’s Sebastian Vettel was third fastest, trailing Rosberg by 1.048 seconds, with this teammate Kimi Raikkonen in fourth and the Williams of Felipe Massa in fifth.
Red Bull’s Daniel Ricciardo did a brief stint at the start with the team’s “aeroscreen” concept, which works like a reinforced windshield. The team released video of the screen deflecting a wheel at high speed, and also a one-kilogram metal projectile similar in size to the metal spring which left Massa with a fractured skull in 2009, when he was driving for Ferrari.
The screen is a rival to a metal “halo” tested by Ferrari last month. Both concepts have come in for criticism over the way they look.
The sport is looking at ways of improving cockpit security to leave drivers less exposed to the risk of head injuries after French driver Jules Bianchi and British IndyCar driver Justin Wilson died last year.
After the screen was taken off Ricciardo’s car, the Australian went on to set the sixth fastest time.
Russian Sergei Sirotkin was 13th in his first practice run for Renault, borrowing Danish driver Kevin Magnussen’s car.
Sirotkin had a brief spell as a development driver for Sauber in 2014.
The only other test driver to take part was 19-year-old Alfonso Celis of Mexico, driving for Force India. He was slowest, more than five seconds off the pace.