MONTMELO, Spain -- The first rule of testing is not to read too much into the headline times. Even so, the paddock couldn't help but sit up and take notice when Sebastian Vettel set a 1:18.161 on the first morning at the Circuit de Catalunya. To give that time some historical context, it was over two seconds faster than the quickest time on the first day of testing last year -- albeit in temperatures 18C warmer this year -- and only one second slower than the fastest time overall from both weeks of testing in 2018.
Given that the opening morning of the test is usually devoted to systems checks and gathering baseline data, Ferrari's ability to hit the track and set serious lap times within the space of a few hours was undoubtedly impressive -- especially as the 2019 regulations were supposed to slow the cars down by 1.5s per lap. By the time the morning session came to an end, Vettel was 1.8s quicker than the next best effort set by Sergio Perez in the Racing Point.
"We couldn't have hoped for a better day," Vettel said after a mammoth 169 laps at the wheel. "I think it was unbelievable. The car was working really well, we had no issues slowing us down, we did the programme just the way we wanted and we were able to squeeze a little bit more out even. The first impressions yesterday [at Ferrari's 100km shakedown] were good and strong and it was the same today.
"To summarise, it's very early, it's the first day, and it'll be meaningless in a couple of weeks, but for now, huge compliments to everyone in the factory. How they have tackled the new regulations and what they put on track today is very close to perfection."
The opposition also seemed impressed.
"Yeah, I've seen the time, it was very quick," Mercedes boss Toto Wolff said during the lunch break. "Two seconds quicker than anyone else -- definitely the Ferrari has been going quick this morning."
Red Bull team boss Christian Horner added: "It's a fantastic time for today. Sebastian has obviously wintered very well!"
But it's become the norm in recent years for the big teams to talk each other up -- especially if they know from their own data that the time is beatable.
Later in the day, McLaren's Carlos Sainz set a time 0.397s off the Ferrari, taking some of the shine off Vettel's morning effort. Sainz was using Pirelli's C4 tyre (the equivalent to last year's ultra-soft) on a track with more rubber on it, while Vettel was using the harder C3 (the equivalent to the 2018 soft) -- and, as always in testing, fuel loads were unknown.
At this stage of testing we don't know the difference in performance between Pirelli's new tyre compounds, but one step between C3 and C4 should be worth something in the region of a second -- while as little as 5kg of extra fuel adds around 0.2s to a lap time. So make of McLaren's lap what you will.
It's also worth noting that Romain Grosjean set a time less than a second off Vettel using the same compound tyre. Given that the Haas was 1.3s off Ferrari in qualifying for last year's Spanish Grand Prix at the same circuit, it starts to add extra context.
But without getting bogged down in incomplete comparisons between cars, it can be said that all the times were relatively quick compared to last year's test. Only the Renaults failed to beat the fastest time from the opening day of testing 12 months ago -- and all that with regulation changes that were intended to cut overall downforce.
Although part of that will be down to the teams claiming back performance with their interpretation of the regulations, it was also down to the track. Not only was the temperature significantly warmer on the opening day of the session this year than it was at any point during the first week of testing last year, the track surface has evolved as the tarmac laid ahead of winter testing last year has weathered in. The rougher the tarmac becomes, the more grip it offers up and in the space of 12 months a circuit can change a lot.
"As usual we measure the tarmac roughness, and if I compare the winter test last year, last year's race and the winter test this year, there is a big evolution in the tarmac," Pirelli motorsport boss Mario Isola explained. "The tarmac was new at the winter test last year, it was very smooth, during the race it was slightly different and now there is a big step again compared to the race.
"Okay, the temperature is playing a big effect [on the lap times compared to last year] and we have to consider that, but there is also an effect that is coming from the roughness of the tarmac."
So should Mercedes and Red Bull be worried? Clearly the Ferrari was quick and reliable out of the box, but that should no longer be a surprise for the top teams. Not only did all three complete an on-track shakedown by using up a filming day ahead of testing (in fact, only Force India, McLaren and Williams opted not to hit the track prior to this week), the components of the top cars will have already completed extensive "mileage" on advanced test benches at their factory. Combined with the shakedown, small problems that may have cost half a day of testing if the car was to hit the track straight away are debugged before the its chassis even arrives on Spanish soil. A luxury some of the smaller teams simply can't afford.
"We had a few issues at the beginning, but that is expected," Force India team principal Otmar Szafnauer said after his team completed just 30 laps on its opening day. "We did not shakedown at Silverstone like some of the teams did, so we had some little niggly bits that you would have caught during a shakedown, but that is all gone now."
Back at the front of the grid, both Ferrari and Mercedes completed over two and half race distances on Monday. The data from all those kilometres will now be fed back to the factory to inform improvements over the rest of testing and ahead of the first race in Melbourne. So even if Ferrari was genuinely quicker than the rest on Monday, it could all change in the next two weeks. And as things stand, the gaps we saw today -- with the information currently available -- means it's still anyone's guess.
"Laps times? You might as well turn the timing monitor off for the first few days of the test, I wouldn't get too drawn into big headlines over the next few days," Horner added. "We've very much got our blinkers on, focusing on our testing programme, and at 16:30 on day one we are content so far."