Mercedes expect three-way fight in 2018 - Wolff

Mercedes chief Toto Wolff anticipates a tightly contested, three-way title fight in Formula 1 in 2018. The Silver Arrows won a fourth-straight crown last year, but Wolff believes Red Bull could emerge ahead of Ferrari to be their main rivals for glory in 2018.

Lewis Hamilton edged Sebastian Vettel to the drivers' crown in 2017, but Mercedes romped to the constructors' title, finishing 146 points ahead of Ferrari.

No team has held a candle to the Silver Arrows in the hybrid era, but team performance has appeared closer than ever in pre-season, with performance levels gradually converging over time.

And Wolff has suggested that Mercedes will be tested to the full this year, with Red Bull having ended 2017 strongly and Renault appearing to have made gains in performance and reliability with their power unit.

Wolff told Sky Sports: "We have a worst case and a best case.

"What we have seen is that even if it is best case we are not in front by a lot, and if it is a worst case we are not far behind.

"What we have seen from Red Bull is that they have a very strong package.

"I think will be very much in the game for race wins and the championship itself.

"I think it will be all three of us against each other.

"Honestly, l am excited by the prospect of a tough battle."

Wolff's comments were put to Red Bull driver Max Verstappen, who completed 130 laps on Tuesday - only Sebastian Vettel (171) managed more.

"We'll find out in Melbourne," he said. "It's too early and I don't want to talk about it."