The 2015 F1 teams' report card so far

The first term of the Formula 1 season is done and dusted with an early pecking order now established.

While Mercedes is top of the class, it's a case of head down and back to work for its rivals ahead of the start of the European season.

Here's how we think the teams have done after the four flyaway races...

MERCEDES
Grade: A
Best race result: 1st
Best qualifying result: 1st
Points: 159
Constructors' position: 1st

Mercedes has effectively picked up where it left off last year, securing three wins from the opening four races - but there's still room for improvement.

The reigning world champion team has a firm grip on the constructors' championship while Lewis Hamilton sits pretty at the top of the drivers' standings, one place clear of team-mate Nico Rosberg.

The only blip in its copybook was defeat by Ferrari in Malaysia, but even then it minimised the damage by taking second and third behind winner Sebastian Vettel.

That weekend was undone by Hamilton losing a whole session because of engine problems, which robbed the team of vital race preparation for what turned out to be a tricky tyre-management situation.

Crucially, it responded well with cleaner weekends in China and Bahrain and the result was two poles and two wins for Hamilton.

Challenges remain, with both Hamilton and Rosberg affected by brake-by-wire issues in the closing stages in Bahrain, causing the latter to lose a position, while the threat from Ferrari is increasing.

But Mercedes is blessed with a driver in Hamilton who is in the form of his life. Rosberg has made a comparatively lacklustre start to his campaign but the team is adamant he will bounce back, citing his more combative race performance in Bahrain.

The W06 remains the class of the field and with big upgrades expected for the next race in Spain, Mercedes has the potential to get even better.

FERRARI
Grade: A-
Best race result: 1st
Best qualifying result: 2nd
Points: 107
Constructors' position: 2nd

Ferrari was in the mire last year but a series of changes from the top down have transformed the Scuderia back into an outfit capable of challenging at the sharp end.

Technical director James Allison has ended a culture of short-term thinking and eased the pressure on the design team.

Team principal Maurizio Arrivabene, meanwhile, has fostered a more harmonious atmosphere in the team and demanded Ferrari build a car that suited Kimi Raikkonen's driving style this season.

The results are clear to see. Ferrari ended a 30-race win drought in Malaysia and consolidated its ability to challenge Mercedes in the next two races.

Along with a heavily-improved chassis and stronger power unit, the Scuderia has been bold with its in-race strategy and aggressive in development.

Vettel is back to his best after a poor season in 2014 while Raikkonen is happy and that is translating into rewards on track.

There is no doubt Ferrari has work to do and it must out-develop Mercedes if it still harbours hopes of challenging for the world championship.

But this has been quite some turnaround and one that shows no signs of abating. If Ferrari applies the same sort of commitment and work ethic when the championship resumes, more wins will follow.

WILLIAMS
Grade: B
Best race result: 4th
Best qualifying result: 3rd
Points: 61
Constructors' position: 3rd

Third place in the constructors' championship was like a victory for Williams last season, especially after a 2013 campaign that yielded just five points.

For an independent team to maintain that kind of form against the big-spending manufacturers was always going to be difficult, but Williams is making a good fist of it - even though on paper its start to 2015 has seemed disappointing.

The team has been rewarded for its consistency with seven points finishes out of eight, which puts it third in the constructors' championship, nearly 40 points clear of Red Bull.

Operationally, Williams needs to sharpen up after errors during pitstops. It also admits that while the car requires upgrades, it is also yet to get the most out of its current package.

Its major weakness centres around tyre usage, with a higher rate of degradation that kicks in far quicker during each stint compared to Ferrari and Mercedes.

Felipe Massa is driving at his highest level since joining the team while Valtteri Bottas was again impressive in Bahrain as he held off Vettel in the closing stages.

Williams performance chief Rob Smedley is confident the team can out-develop its rivals, and it will need to if it harbours hopes of holding off the inevitable fightback from Red Bull.

RED BULL
Grade: C-
Best race result: 6th
Best qualifying result: 4th
Points: 23
Constructors' position: 4th

After four races, a best finish of sixth for Red Bull is quite simply not good enough for a team that is used to winning championships.

A very public spat with engine supplier Renault has not helped matters and though they have shown a united front of late, the partnership remains up against it.

The team is still struggling to set the car up properly, while Daniel Ricciardo is already on the fourth and final engine of his allocation - and there are still 15 races to go.

Even if a regulation for a fifth engine is pushed through, it's a case of when and how many rather then if penalties are taken for Red Bull.

To be fair to Ricciardo, apart from a mistake off the start in China that cost him a host of places, he has done little wrong.

His team-mate Daniil Kvyat has had it tougher, with a low point of getting knocked out in Q1 for the first time in his career in Bahrain, and he is still searching for a trouble-free weekend.

But Red Bull proved last year that it is capable of rescuing itself from a tricky situation. Only this time, those looming engine penalties will make it just that bit harder.

SAUBER
Grade: B
Best race result: 5th
Best qualifying result: 9th
Points: 19
Constructors' position: 5th

Last season was the low point in Sauber's 22-year history as it failed to score a point and ended up last of the surviving teams in the constructors' championship.

And things got worse before they got better when the Swiss-outfit arrived in Australia with three drivers laying claim to two race seats.

After Sauber came to an agreement with Giedo van der Garde, which resulted in the Dutchman dropping his legal right to drive for the team, things started to look up.

Boosted by a vastly-improved Ferrari power unit and an all-round better chassis, Sauber scored a double-points finish in Australia, headlined by Felipe Nasr's fifth on his debut.

Another double-points haul came in China, while points were possible in Malaysia and Bahrain, too, had Marcus Ericsson not spun out at the former and had a pitstop issue in the latter.

With a big upgrade package unlikely for Spain and the team yet to get the most out of the front wing it introduced a couple of races early in China, maintaining this kind of form will be tricky.

But considering where it finished last year, the Swiss team is on course to do better.

LOTUS
Grade: B-
Best race result: 7th
Best qualifying result: 8th
Points: 12
Constructors' position: 6th

Romain Grosjean said this month that he wished he could delete 2014 from his racing career, such was the disappointment of that season for him and his Lotus team.

However, Lotus showed promise in pre-season testing and while it remains a couple of steps off returning to its race-winning form of 2012 and '13, it has certainly moved up the pack.

Claims of being the fourth-fastest car behind Mercedes, Ferrari and Williams are probably a touch ambitious, with Red Bull arguably still ahead of Lotus on pace.

But Lotus already has more points after four races than it managed to achieved during the whole of last season, with Grosjean's seventh places in China and Bahrain getting the most out of the package.

Pastor Maldonado may have failed to score points and made some rookie mistakes - like accidentally switching off his engine during a pitstop - but he has showed good pace, particularly in the last two races.

The Venezuelan now needs to get his act together, Grosjean must keep delivering and the team has to focus on getting on top of its balance issues.

TORO ROSSO
Grade: C+
Best race result: 7th
Best qualifying result: 6th
Points: 12
Constructors' position: 7th

Toro Rosso raised eyebrows when it named an all-rookie line-up for this season with Carlos Sainz Jr and Max Verstappen but the move is already showing signs of paying off.

Sainz scored points on his debut while Verstappen, 17, became the youngest-ever F1 points scorer at the following race in Malaysia.

The team's tactic of focusing on mileage in testing to prepare the drivers for their debuts has proved crucial, with Sainz and Verstappen hitting the ground running and impressing engineers with their work ethic and the quality of their feedback.

The Italian team was fifth in the constructors' at one point, above sister team Red Bull, but has since dropped down the field after a bafflingly uncompetitive showing last time out in Bahrain.

Like Red Bull, Toro Rosso has been hampered by issues with its Renault power unit. Both drivers cite the engine as the main area that requires improvement.

Only small upgrades are planned through the season, with the main development package having been introduced for the final winter test, so Toro Rosso needs that power boost sooner rather than later.

FORCE INDIA
Grade: C
Best race result: 7th
Best qualifying result: 8th
Points: 11
Constructors' position: 8th

The opening four races were always going to be difficult for Force India following delays with the manufacturing of the 2015 chassis and the upheaval of switching windtunnels.

The team admitted its initial target was to score points where possible until its B-spec car makes its expected debut at June's Austrian Grand Prix.

The fact Force India has notched up 11 points, including a double-points finish in Australia, and is within touching distance of its main rivals Sauber, Lotus and Toro Rosso is something of a triumph.

Things will get harder, especially with some other teams expected to bring upgrades to Spain, which is the first of three races before Force India's updated machine hits the track.

But the team's ingenuity with strategy, such as Sergio Perez using a two-stopper to score points in Bahrain, has paid dividends. More of the same will be required in the coming races.

McLAREN
Grade: C-
Best race result: 11th
Best qualifying result: 14th
Points: 0
Constructors' position: 9th

That only two teams have failed to score a point in the first four races of the F1 season is not unusual. The fact that one of those teams is McLaren certainly is.

It's been a painful start to the revived McLaren-Honda partnership, with only a pair of 11th-place finishes to show for the start of the campaign.

But the team is at least making progress race-by-race. While it locked out the back row at the season-opener in Australia, Fernando Alonso proved in Bahrain that the team is now capable of making it into Q2.

In the races, while Jenson Button's 11th place in Australia was a lap down, Alonso was just four seconds off a point when he achieved the same position in Bahrain.

A significant upgrade to both the chassis and the engine package, the latter of which has proved particularly problematic, for Spain is expected to lift the team into the top 10.

But as encouraging as that is, the frontrunning teams that it ultimately measures itself against have major developments on the way too. It could be a long season.

MANOR
Grade: C-
Best race result: 15th
Best qualifying result: 18th
Points: 0
Constructors' position: 0

At one stage, it looked like Manor wouldn't even make the grid, so the fact it got to Melbourne (albeit only the garage) and then competed in the next three races is an achievement in itself.

Software issues prevented Will Stevens and Roberto Merhi from starting the race in Australia, but Merhi got the car to the chequered flag in Malaysia.

Both cars finished in China and Bahrain, too, and Manor is now able to comfortably lap within the 107 per cent cut-off time in qualifying.

But the path ahead is steep, with the 2015-spec car not expected to make its debut until after the summer break.

Stevens has a deal for this season, but Merhi's future is up in the air and the state of the team's finances is key to whether he keeps his seat or not.

The rest of the season is going to be a struggle, but the team looks like it has the stomach for the fight.