Mercedes F1 team technical director James Allison believes the Red Bull team could be Mercedes’ biggest rival in 2018.
Allison has been impressed with the pace of the Red Bull during pre-season testing. On day two of the second test, Daniel Ricciardo’s Red Bull RB14 set the fastest ever lap of the Catalunya circuit in Barcelona, almost half a second clear of Lewis Hamilton’s Mercedes.
"I think there's three quick teams and there's no doubt that Red Bull are going to be people that we're going to be fighting with this year," Allison told Sky Sports.
"It's still not possible to say for sure if we've got our nose in front of them or they've got their nose in front of us, but you can say it's close.
"I don't know what their engine plans are, but looking at what they've brought here, I'd say they've still got some bodywork to bolt on before Melbourne.”
Encouragingly for Red Bull, while fellow Renault-powered team McLaren has struggled to find reliability during the tests, Ricciardo logged 165 troublefree laps.