The first week of testing offered the first glimpse of how the 2019 Formula One season might pan out. It's still early days and a lot can change in the second week, but below is the order we think the teams line up in after the first four days of the pre-season.

Ferrari

Ferrari looked like the team to beat in the first week of testing. Andrea Diodato/NurPhoto via Getty Images

Quickest lap time: 1:18:046 (Day Four, C3 tyre)

Total laps: 594 (2nd out of 10)

However you adjust the times for fuel and tyre compounds, the Ferrari comes out as the fastest car. On the first day of testing, Sebastian Vettel set an astonishingly quick time -- a 1:18.161 -- on Pirelli's C3 compound and immediately Ferrari's rivals sat up and took notice. With no immediate reference it was hard to read too much into it, but as the week progressed it became clear that it was a very quick lap by the new standards of the 2019 regulations. By the final day, Charles Leclerc had improved on that lap by 0.115s but the impressive thing was that he managed it at the start of a long run when the car would have been carrying a significant amount of fuel.

On track, the car looks planted and the drivers were able to push to the limit very early on. The team opted not to use either of Pirelli's two softest compounds all week, yet in the first sector the SF90 was still quicker than the pace-setting Renault on C5s -- hinting at the level of performance potential locked away in the car. The team has not yet completed a race sim, but Ferrari usually saves that for the second week when more new parts come to the car and the weather in the afternoons is a bit warmer. Expect to see some even quicker times when the softer compounds go on, and be sure to make a note of them because they will be the reference for everyone else.

Red Bull

Red Bull looks solid but has yet to venture onto the softer compound tyres and low fuel. JOSEP LAGO/AFP/Getty Images

Quickest lap time: 1:18:780 (Day Four, C3 tyre)

Total laps: 468 (5th out of 10)

Red Bull exuded confidence in the opening week of testing but, frustratingly for onlookers, opted not to show its hand in terms of performance. The team stuck to just the C2 and C3 compounds over relatively long runs, as well as a small amount of laps on Pirelli's prototype tyre, which is a variation of the C3. That left them as the eighth fastest team overall, but strip away the fuel and correct the time difference for tyres and the RB15 looks quick.

A rear wing upgrade arrived on day three of the test, and with it we started to see hints of the car's true potential. Pierre Gasly's fastest time -- a 1:18.780 -- was over 0.9s off Leclerc on like-for-like tyres and only 0.020 quicker than a Lewis Hamilton lap on harder C2 tyres, but it was set at the start of a much longer stint than the Mercedes and a slightly longer stint than Ferrari. That means Gasly was on a heavier fuel load and the lap, although not impressive on face value, comes loaded with the promise of a much faster time in the second week.

If there were any concerns about the reliability of the Honda power unit they appear to have been allayed by a lap count of 468 from the first four days. Combined with speed trap readings that are consistently in the same ballpark as Ferrari and Mercedes, and the early signs are that the Japanese manufacturer has recovered decent ground over the winter. You can guarantee a big aero upgrade is in the offing for the second week, and with it Red Bull will be hoping to match Ferrari through the corners.

Mercedes

The Mercedes W10 seems to lack rear stability in high-speed corners. Marco Canoniero/LightRocket via Getty Images

Quickest lap time: 1:17:857 (Day Four, C5 tyre)

Total laps: 606 (1st out of 10)

After so many years of Mercedes dominance, it was assumed that they would be the benchmark team in testing last week. Yet all the evidence from the first four days of testing suggests the team has not made the same performance gains as many of its rivals over the winter. Reliability wise the car is up to the high standard expected from the world champions, but when the team tried to extract performance from the W10 on the final day it was found lacking. The car looks unbalanced in high-speed corners even after Mercedes spent a large chunk of the first three days tinkering with setup changes.

The W10 is losing most of its time to its rivals in the middle sector (including 0.25s to the Ferrari) where high-speed direction changes are key and a stable rear end is essential for committing fully to the uphill section through Turns 7, 8 and 9. A Lewis Hamilton lap on the C2 tyres on Thursday was Mercedes most impressive of the week given the hard rubber being used, but the team failed to find the performance gains it would have hoped for from the softer compounds. Its sector one times looked good, but there was a big tail off further round the lap as the tortured rubber struggled to hang on. Struggling to balance the front and rear axles on softer compounds is a trait we have seen from pervious Mercedes cars and could be a hint that the "diva" qualities of the 2017 car, the W08, have resurfaced in the W10.

Like all the top teams, Mercedes will bring a significant aero upgrade to the second test and the hope will be that more downforce helps solve some of the issues it faced in the first week. However, there is little doubt that the world champions are playing catch up and it will require a significant step to bring them level with Ferrari ahead of the opening round in Melbourne next month.

Renault

Renault stole the headlines with the fastest time of the week but also looks quick off the softest compounds. Xavier Bonilla/NurPhoto via Getty Images

Quickest lap time: 1:17:393 (Day Four, C5 tyre)

Total laps: 431 (7th out of 10)

Finishing the first week with the fastest time was promising for Renault. A rear wing failure caused by the DRS mechanism was cause for concern on day two, but the team bounced back and when it came to performance runs on the softer compounds it found a decent chunk of time.

Nobody was quicker through sectors two and three last week, hinting at a car that is stable in both high-speed and low-speed corners. The third sector was particularly impressive given that Renault was over a tenth faster than Ferrari and Mercedes and at least 0.4s quicker than its midfield rivals. Given that the softest compounds are usually struggling by the end of the lap, it also hints at a car that is kind to its tyres.

By its own admission, the team struggled to get its car ready in time after leaving the build as late as possible to spend more time developing its concept in the wind tunnel. That means updates might be a little bit slow coming to the car next week as the factory in Enstone tries to make up for lost time, but the early indication is that the extra time dedicated to development is paying off.

Alfa Romeo

The Alfa Romeo has shown potential across the tyre range. Dan Istitene/Getty Images

Quickest lap time: 1:17:762 (Day Three, C5 tyre)

Total laps: 499 (3rd out of 10)

Kimi Raikkonen set Alfa Romeo's fastest lap time of the test on the C5 compound, but it was a lap from Antonio Giovinazzi on the C3s that stood out. It was less than 0.5s off Leclerc's C3 time that has been heralded as the benchmark for the opening week and came on a relatively long run with a healthy tank of fuel.

When you consider where the team was 12 months ago and the progress it made last season, there is a real reason to be excited about how the C38 will perform in Melbourne. The front wing seems to be a similar concept to the Ferrari's but on a more extreme level, while the rest of the car follows a slightly different development path. So far the combination seems to be working and there is reason to believe that it could be towards the front of the midfield early in the season.

Alfa Romeo also had the third highest testing mileage behind Ferrari and Mercedes -- another promising sign as reliability is always a factor in the midfield battle at the start of the season.

Haas

The black and gold Haas looks quick but has also had reliability issues. Dan Istitene/Getty Image

Quickest lap time: 1:18:563 (Day Four, C3 tyre)

Total laps: 379 (8th out of 10)

Haas' low-key first week is slightly misleading. It did not replicate the headline-grabbing times of Renault or Toro Rosso in the second half of the test but a closer look at the best laps of Romain Grosjean and Kevin Magnussen give reasons to be optimistic. Both drivers recorded their quickest laps on the C3 tyre, rather than the C4 or C5, and when "tyre corrected" the American team was in the same ballpark as Red Bull, Mercedes and the impressive-looking Alfa Romeo. Believing Haas or Alfa have overturned the significant gap between the front three and the midfield over the winter is a tad optimistic, but it's clear both Ferrari customers have a lot of raw pace to unlock inside their race cars.

The major and most obvious blot on Haas' week was the succession of issues that chewed away at its potential track time over the four days, leaving it with the third-lowest lap count. A fuel pressure issue halted Romain Grosjean on Monday, Kevin Magnussen's first day with the car was cut short due to discomfort in his race seat, and the team went on to suffer three separate electrical issues on Wednesday. But none of those were disastrous and a clean day followed on Thursday, with its biggest single-day haulage of 130 laps between both Grosjean and Magnussen. Depsite its hiccups Haas believes it has a good package to work with at this stage of the winter, although it needs a smooth second week to get the best out of it.

Toro Rosso

Toro Rosso set the second fastest time of the week. Peter Fox/Getty Images

Quickest lap time: 1:17:637 (Day Four, C5 tyre)

Total laps: 479 (4th out of 10)

Quick lap times on the C5 compound saw Toro Rosso top Wednesday's session and come up just short of Renault with the second fastest time of the week. It had the fastest car of all in the first sector and lost the majority of its lap time in the final sector -- most likely due to the drop off the C5 tyres experience over the course of the lap.

All the signs so far suggest the Honda power unit is not causing any issues and is delivering a respectable amount of power. The team will bring an update to the second test that should keep it in the battle with the other midfield teams, but it is hoping to buck the trend of recent years where it starts strong and drops off. As a result, further major developments are expected later in the year that means the car could accelerate up the order even if it starts 2019 outside the top ten.

McLaren

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Quickest lap time: 1:18:431 (Day Four, C4 tyre)

Total laps: 440 (6th out of 10)

You can tell McLaren is serious about the humble approach it has adopted in relation to the coming season -- we've heard none of the bravado which accompanied previous winters and the team was perhaps one of the quietest all week. Maybe that was because there was no Fernando Alonso in the car, but the team seemed to have gone out of its way not to make a song and dance about its solid start to pre-season. McLaren is realistic about the task at hand and the forlorn expression on Carlos Sainz's face after his first day in the car suggests he is starting to appreciate the scale of it.

Although it set some times which looked impressive at face value, deeper analysis suggests McLaren is still at the lower end of the order at this point in the year. But there are reasons the team can be happy. Most notably, and likely to be of most relief, is that McLaren has enjoyed a fairly ordinary test so far in terms of reliability -- this week there was no repeat of the long, alarming delays of recent years which ate into potential track time. It had a slightly late start on Wednesday and Lando Norris beached his car in the gravel on Thursday morning, but had you offered those two examples as the team's most significant stoppages going into the week it probably would have gleefully accepted. It's clearly a work in progress, but there are glimpses of that progress and that's the best pre-season news McLaren could have hoped for at this stage.

Racing Point

Racing Point have yet to show much promise. Andrea Diodato/NurPhoto via Getty Images

Quickest lap time: 1:19.664 (Day Four, C2 tyre)

Total laps: 248 (9th out of 10)

Excluding Williams, the team formerly known as Force India had the worst week of testing. Its lap count was nearly half of some of its midfield rivals and its lap times were nothing special. Despite using the C5s and C4s, the fastest lap came from Lance Stroll on C2s. That suggests the team still has performance locked away in the car for the second week but there was no shying away from the fact that car was lacking performance in all three sectors.

And yet, we are still reluctant to discount the team from the heat of the midfield battle come Melbourne. Under its pervious ownership, Racing Point often looked like one of the weaker teams in testing, only to turn up at the opening races and bag a decent haul of points. What's more it has a reputation for frugal and fast development, and with a proper budget in place this year it should be able to harness the potential of its very talented work force and push back towards the front of the midfield. But for now, there is still some serious work to do in the second week of testing.

Williams

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Quickest lap time: 1:20:997 (Day Four, C3 tyre)

Total laps: 88 (10th out of 10)

Claire Williams called her family team's start to 2019 "embarrassing" and it was hard to disagree. A delay in finishing its car spilled over into two whole days of testing missed -- the team only rolled out of the garage in the afternoon of day three. Most of Wednesday limited track time was dedicated to the system checks most other teams had completed at filming days held before testing even started, meaning the 75 laps completed on Thursday can be considered its first meaningful running of the season so far.

It is obviously impossible to judge the performance of the FW42 when it is so far behind schedule, but clearly Williams faces a mammoth task in making up for lost time next week and ensuring it avoids any further delays. The late arrival of its car does not automatically mean the car is a dud, but the late start and the fact so many of its rivals appear to have made a good step forward means it is already on the back foot going into the final four days before Melbourne. Williams needs to accumulate good mileage and, crucially, as new parts arrive, set some promising lap times to provide a glimmer of hope that 2019 won't be another wasted year.