Wolff: Three-way battle will intensify in Spain

Speaking ahead of the weekend in Barcelona, round five of the Formula 1 world championship, Wolff said, "After an exciting start to 2018 we're now heading into the European season with races like Spain and Monaco that present very different challenges than some of the previous tracks."

"Overtaking is difficult in Barcelona and even more so in Monte Carlo, making track position key for a good race result. So every team will work hard to get every last bit of performance out of the car in qualifying."

"The European season is also the time when teams start introducing bigger upgrades to their cars. It's the first step of the development race that looks like it could run to the very end of the season."

"It will be interesting to see how much performance the teams can find with their upgrades and what impact those upgrades will have on the team ranking - both at the front and in the midfield.

"Barcelona holds mixed memories for us - a double DNF in 2016, but also a dramatic win for Lewis last year after passing Vettel on track for the lead. We're hoping that this year's Spanish Grand Prix will be a good race for us, but we know that it will be tough."

"The first four races indicate very strongly that we will see the three-way battle continue and - if anything - intensify," added Wolff.

With four races run so far, Mercedes finally opened their account with an unexpected victory in Baku last time out, while Red Bull's Daniel Ricciardo won in China and Ferrari's Sebastian Vettel won the first two race of the season.

Ferrari lead the constructor's championship from Mercedes by four points, while Hamilton tops the drivers' standings from Vettel also by four points.