FrukostScones wrote: ↑14 May 2018, 12:25
But we know those tyres were not really working like intendend for some teams (S faster than SS etc.), but one team was flawless on them and dominated (look at BOt 2nd stint).
You are mixing up some things here, that being the 0.4mm and the S faster than the SS. One hasn't got anything to do with the other. The SS is the softest tire, but it has a very narrow operating range. That means there's a smaller sweet spot where the tire operates at its best. The problem at Barcelona, especially during FP2, was the high track surface temperature (40°+). Because the tarmac is so dark, it doesn't reflect sun light much and heats up significantly.
With the high downforce and high speed corners track layout (especially S1 and S2), it heated up the tires significantly and pushed them over the operating range. The result being that the tire overheated towards the end of the lap. This isn't anything new or unheard of - it's just due to many factors playing together. A different track where the layout is different may not have this problem etc. Everyone had issues with the SS tire in FP2. On Saturday, temperatures were overall much cooler (track surface temperature around 30°C) which worked out better for most teams on SS. Even so, I can imagine that teams had to tip toe around on the SS to get the best out of it over the entire lap; i.e perhaps push less in S1 to not overheat them in S3 etc. Some cars got it better, some worse.
In the end, the soft tire was probably the faster tire for pretty much all the teams in qualifying, as it's a harder tire, has a wider operating range and wasn't suspect to overheating as much as the SS. The only reason Mercedes didn't use a soft tire for their second Q3 run is because they already had pole with Hamilton and because the soft tire was the tire to be used for the race, it made more strategic sense to save the extra set for the race. Ferrari was way down the order, even behind both RedBulls, so they had to take a gamble. They used their only remaining set of soft tires and indeed could do a better lap on them and at least ended up on the 2nd row. Mercedes IMO was lucky to retain pole position.
Unfortunately for Ferrari, this also meant that they used up all their soft tires, so for the race, they only had the soft they were already starting on and two new mediums (that they then used for Vettel for stint 2 and 3).
Also, and again, those crying and whinging about Mercedes and the 0.4mm thread change; Mercedes was already dominant in winter-testing. They were dominant in Melbourne. They obviously have a very quick car. In 3 of the last 5 races, they struggled on mainly the Ultra-Soft tire in qualifying, but always had strong pace on the harder tires during the race. With all the data they had from testing, it shouldn't be that surprising that Mercedes was strong here. I would also point out that the intel after winter-testing suggested that Ferrari had to save fuel. It's not that far fetched that Ferrari may have also had to save more fuel than Mercedes again yesterday during the race and that this is part of why the Mercedes seemed so dominant.
The Mercedes already demonstrated a huge dominance in Melbourne this year which shows that the car is very fast in the right conditions and when using the tires correctly (just like that the Ferrari is extremely fast when it hits the tires sweet spot).