Renault reserve driver Sergey Sirotkin was with the team for the pre-season test in Barcelona – and got to watch the field of F1 2017 out on track. Below, the SMP Racing protege recounts his impressions.
That Formula 1 teams test their new cars in Barcelona is not just by chance. It's a track everything is long known about – and it's got the appropriate selection of corners to provide exhaustive information about car behaviour. Even watching the cars trackside, you can still come to certain conclusions.
Of course, it's impossible to get the full picture as we don't know what programmes the teams are going through, what settings they use, how much fuel is in the cars at any given time and what the exact goal is of each run.
So instead we'll focus on just some of the interesting features of the behaviour of the different cars in the field.
Sector three
One of the most interesting points to watch F1 cars from is the third sector of the Barcelona track. From the grandstand there, you get a great view of the whole sequence of corners. And this time through here, it was the Ferrari that looked the best.
That car has made the strongest impression so far, both in terms of laptime and in how the car looks out on track. Sector three in particular shows how well-balanced it is and how quick it is. And that has to do with both chassis and engine.
There's not a lot of space between various corners in sector three, and it's particularly noticeable, that the SF70H is no worse than the Mercedes in terms of acceleration - perhaps better than it, at certain points.
If you look at analogous runs in terms of lap count and tyre choice, the Ferrari stands out. It's a very stable car in the middle and end of braking. Corner entry is visibly quicker than it is for other cars, and the rear remains stable through the whole corner.
For many of the other cars, the rear looks twitchy under braking, and there's obvious understeer on corner entry. The Ferrari's completely different. It's steady heading into the corner and, at the midway point of the corner where the driver has to make a sharp turn and get back on the throttle, it follows the movement of the steering wheel well and turns in.
As a result, the car ends up in such a position that the driver can very comfortably begin to accelerate right away - the Ferrari goes through the corner in what we could call a 'V-shape': fast entry, sharp turn, exit.
From this, you can gain a lot on corner entry and exit. And, because this car doesn't suffer from understeer within the corner, the drivers can spend a lot less time navigating it.
All of this looks great out on track, very impressive, especially the whole sequence between Turns 12 and 14, the entry into the chicane.
The speed at which the Ferrari can change direction in the middle of the corner is what allows it not to lose time on the apex compared to its rivals – for instance, the Mercedes, which seems to be behaving a bit differently.
The W08 is the only car that looks to be on pace with the Ferrari, although of course we don't know what the programmes of the various teams were throughout the test.
I've watched the Mercedes for a few days, and in details the car behaviour naturally tends to differ quite a bit from run to run. But in general the car does seem to encounter oversteer a lot more than Ferrari. That doesn't really affect the pace that much, but it does mean the car is less stable.
The Mercedes pair preferred to take corners in a U-shape. Since the rear end of the car is less stable, you can't attack the corner as rapidly – and you can't accelerate on corner exit as sharply. Yet on the apex itself the Mercedes retains more speed, as if rolling through the turn.
If you have a lot of grip on the front, you can keep a higher minimum speed through the middle of the corner. But if you don't have the grip, you have to attack on entry, then make a sharp turn and drive away – while losing time in the middle of the corner through understeer.
Ferrari doesn't have the issue and its drivers can afford this approach. The SF70H's rear is more stable than the Mercedes' – these two cars are completely different in that area.
The W08 also looks fast, but on long runs the deficit in chassis stability becomes more and more obvious. First it's once every two laps, then it's once a lap, and when the tyres are already worn, you can see it not in every corner, but almost consistently – a little bit here, a little bit there and so on.
It's very hard to gage the power units, because we don't know about the particular engine modes, but even there the Ferrari looked a bit quicker, while the Mercedes stood out against all those remaining. But there's no huge surprise in that.
Turn 9
Another interesting spot is the high-speed Turn 9 that precedes the back straight. Watching cars here, you can make a few judgements in regards to aerodynamic balance, how the car behaves at maximum aerodynamic load and whether that's spread evenly between the axles.
You can also see how the suspension reacts to bumps, as even the tyre marks here make it clear how rough the surface is.
Last year, drivers had to lift a fair bit through here, and would even sometimes apply a little bit of braking before corner entry. Now speeds are 30km/h faster and the leading cars pass through Turn 9 at full throttle.
It is so impressive. Back in 2013, in the World Series by Renault, before all the changes aimed at lowering speeds, we were also able to attack Turn 9 at full throttle, but at the very limit. I did it maybe once or twice. Right now, the Ferrari and the Mercedes, they consistently tackle it without lifting.
It's the same picture again: the Ferrari looks best. Pedal pushed to the floor, very fast, very steady. At one point the Force India was running close to it on track, and it was obvious how much the car was reacting to the bumps. But the Ferrari looked on rails.
It's a very difficult spot for the suspension. First of all, the car approaches the corner already on almost maximum load. Then in the corner itself you get more load from the side, and the bumps stress the suspension further.
The suspension has to work well at maximum load there, and the Ferrari does. The car remains stable, partly because of better aerodynamic grip but also, of course, because of the work of the suspension itself.
The Mercedes also attacks Turn 9 at full throttle, and with an upshift on corner exit, too. So the car doesn't just pass through the corner at a high constant speed, but continues to accelerate. It's something you can't get tired of seeing.
For contrast, you can look at the Williams. Even on soft tyres its drivers have to lift – you can hear it very well on corner entry. Maybe they don't completely take the foot off the throttle, but they do need to lift at least a little bit.
The car wobbles, the front wing almost scraping the asphalt. That means, firstly, that the car simply doesn't have as much downforce and, secondly, that the suspension isn't handling the bumps as well.
Prior to Turn 9, there's the sequence of the left-hander Turn 7 and the right-hander Turn 8. A very quick switch, with an elevation change to boot.
The tendencies there are the same as sector three. The W08 on exit of Turn 7 starts to turn earlier and thus gets to the outside kerb much sooner than the Ferrari. From there the driver has to get around Turn 8, making for a wave-like trajectory.
The Ferrari, meanwhile, makes a sharp turn at one point and then continues to accelerate in a straight line. Now, you can't be absolutely certain that that's the faster way, as it depends also on the car balance, but it is a confirmation of the car behaviour trend.
Red Bull, Williams, Force India
To be honest, it's quite difficult to reach any conclusions about Red Bull's form, because the team spent less time out on track, and I saw the car much less frequently than the Ferrari and the Mercedes.
With that in mind, in terms of chassis behaviour, the RB13 looked a bit like the Mercedes, but perhaps more steady in certain parts.
For example, in Turn 12, where the Ferrari enters rapidly, turns and immediately gets on the throttle, Red Bull's drivers don't turn the steering wheel fully, as if on purpose, midway through the corner, but then get on the throttle earlier and more smoothly, allowing the car to go very wide.
The minimum speed in that case is higher, and the driver gets on the throttle sooner, but it's not as sharp and not as fast. It looks as if they're losing speed on entry. But again, there's no guarantee the car, when I saw it, was running in similar conditions to the others.
As for the power unit, in the engine mode that I saw Red Bull use the deficit on power compared to Ferrari and Mercedes was noticeable. Whatever the step forward that Renault has made, it's still a little bit behind.
). I see there's a rebroadcast at 15:00 though so I will be on spoiler alert mode until then. The rebroadcast runs until 17:00, when the MotoGP starts so Sunday afternoon motorsport needs are well catered for 
