After four years in the doldrums with a tough to tame ground-effect car, Toto Wolff's Mercedes empire was desperate to strike back. The combined efforts of its chassis team in Brackley and its power unit division in Brixworth came up with a rocket ship, but enduring reliability problems are taking its grade down to A-.

The good

Mercedes came out of winter test as the odds-on favourite for the new era with a strong chassis, powerful engine and top-of-the-line energy deployment, reminiscent of its 2014 dominance. Qualifying in Australia appeared to confirm as much, with George Russell and a vastly improved Kimi Antonelli miles clear of the competition, and the team would go on to sweep the first 10 qualifying sessions and win the first six grands prix in a row to take an empathic lead in the standings.

Antonelli's run of five consecutive wins was particularly impressive off the back of a troubled rookie campaign, with the Italian teenager cutting a much more confident and steadfast figure as he developed into an elite title contender.

The young Italian looks like the man to beat, leading Lewis Hamilton by 50 points at the break with team-mate Russell another nine points behind. Mercedes is also sitting pretty in the constructors' standings, holding a 72 point lead over nearest chaser Ferrari.

Andrea Kimi Antonelli, Mercedes

Photo by: Guido De Bortoli / LAT Images via Getty Images

The bad

But that lead could and should have been a lot bigger if it hadn't been for a significant number of reliability issues, particularly on the power unit, which have plagued both the works team and some of its customers. Russell suffered a dramatic retirement from the lead in Canada, while Antonelli also suffered misfortune with crippling electrical issues in Barcelona.

Mercedes has responded by bringing reliability improvements to its battery pack, but that will come at an additional cost of grid penalties down the line. Meanwhile, Ferrari and McLaren have made huge strides in the chassis side to close the development gap, which enabled both teams to win races on merit before the summer break. Mercedes is still planning its own upgrade rollout, however, which should reinforce its position at the front.

Another challenge for Mercedes is trying to get the most out of Russell, who has comparatively struggled more than his team-mate to get to grips with the new energy deployment rules and has come under pressure to match Antonelli in what he felt should have been his year to shine.

George Russell, Mercedes

Photo by: Brett Farmer / LAT Images via Getty Images

What they're saying

Toto Wolff, team principal and CEO: "We haven't brought an upgrade for some time and you can see that this is going to be a development fight going forward. We need to be really just being strategic about when to bring the upgrades, when do we think they will have the biggest impact on performance, rather than just throwing it in at every grand prix like in the past. We've tried to have it a little bit more in the second half of the season.

"Even though the gap is 50 points, there are so many races to go. A DNF or two can just swing massively and we've not been great on reliability, so we just have to continue to maximise every single day from the Friday onwards to the Sunday and then hopefully at the end that will be enough."

We want your opinion!

- The Motorsport.com Team