Red Bull team principal Christian Horner is "under no illusions" that Mercedes will be the team to beat in Formula 1 this season.
Whilst seven-time consecutive world champions Mercedes struggled throughout the three days of testing in Bahrain, Red Bull laid down a marker with consistently fast times in both qualifying and race simulations.
Compared to the lively Mercedes which twice caused Lewis Hamilton to spin, the RB16B looked comfortable in the hands of both Max Verstappen and Sergio Perez - the former setting the fastest time of winter testing.
Despite its strong showing, Horner was adamant Mercedes remain the title favourites.
"It's so much dependent on what Mercedes do," Horner said. "They've been formidable opponents over the past six, seven years.
"Obviously very much the benchmark, and continue to be that benchmark.
"We've worked very hard in all areas of the team in what has been a short winter. It's been challenging conditions for everybody but the whole team has responded very well.
"It's going to be great to get racing again in a long year, and we are under no illusions that Mercedes are favourites going into this year."
Verstappen's fastest time of the three-day test was set on the final evening of running, his one minute 29.960secs over one second faster than Hamilton's best effort from the same session.
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