We found out what the new Williams looked like, Fernando Alonso managed his first track time of 2013, Adrian Sutil got back in a Force India and Jean-Eric Vergne drove on "cauliflowers".
The first running at Barcelona should start to give an indication of who will be strong in Melbourne, but with everyone wanting to play down expectations, it was still a pretty confused picture. Here's what we learnt:
The degradation of the new Pirelli tyres is very high in cold conditions. Frighteningly high. Torro Rosso's Jean-Eric Vergne described them as one-lap tyres, "like cauliflowers". Lewis Hamilton put in a fast lap in his Mercedes W04 and then a handful of laps later was four seconds a lap slower. Sergio Perez said if the tyres continued like this there would be seven to ten pitstops per race: "The degradation is very difficult. It's a big surprise. Normally in winter testing we see a lot of degradation, but never this much." A touch of realism was added by Lotus's Eric Boullier: "We saw last year when it was cold that the tyres were completely out of the range, graining and degrading a lot. We need to wait now to have hotter temperatures to see how the tyres are working and if there is a big difference. We had this same rubber on the Friday in Brazil and it wasn't so bad."
Sergio's McLaren team-mate Jenson Button is heartened by the consistency of the 2013 Pirelli tyre: "This year is more difficult in terms of graining than last year, but in terms of understanding the tyre it's much easier. You can get (the tyre) in its working range, and you know by lap three or four it's going to start graining. So compared to last season, it's more of a level playing field."
The characteristically secretive Red Bull team are being extra secretive about their rear end this year. The closer we get to Melbourne, the closer the cars are going to resemble their final form and the closer the photographers will want to get. In testing they're allowed to erect screens, but that doesn't stop people poking cameras over the top of them!
Barcelona is traditionally the venue where teams will start running race simulations and Romain Grosjean put in a 66-lap run which included a 24-lap stint where his pace was steady around the 1.29s mark. The lack of tyre degradation was impressive, although the headline times were in the 1:22s bracket. Expect many more race simulations in Barca 2 next week.
Everyone was very keen to talk down their chances and their testing form. Eric Boullier wasn't getting carried away by Grosjean's times pointing out that none of the cars were in Melbourne spec. Jenson Button was keen to point out that although the McLaren MP4-28 had been quick in Jerez from time to time, they don't know if 'x' will cause 'y'. "It's been very tricky to understand where the car is," a candid Jenson told reporters. "At times the car feels good, at other times it doesn't. A lot of that is basically understanding the car that we have and understanding the way it's working and making sure it's working the way we expect it. Some of the time that hasn't been the case."
Lewis Hamilton more than anyone was keen to dispel the idea that Mercedes were going to be any good in 2013. "Vettel and maybe Fernando (interesting that it's the surname for his rival and first name for his mate) were saying I'm maybe going to be competing for the world championship, but I really don't see that happening at the moment. Of course that's our goal but you've got to remember the car was over a second off, sometimes two seconds off, last year and we've not caught a second up... And other teams will have put a second on over the winter. So we've not gained three seconds, that's a fact." So expect him to be in contention right from the start...
Drivers don't particularly like testing in hail which pelted down on the Circuit de Catalunya midway through the final day. Mark Webber was phlegmatic as ever: "Actually, conditions were pretty consistent, pretty stable, although probably not very representative of what you would have on a grand prix weekend..." and then he remembered something; "maybe Nurburgring on a Saturday morning."
Esteban Guittierez made the most of the wet and slippery conditions to learn how to chuck his Sauber about in the wet. With most teams reducing their lappage on the final day he was free to explore many parts of the circuit.
Adrian Sutil returned to an F1 cockpit for the first time since November 2011 and considering the absence did a very respectable job on tyres he's had no experience of. Sutil's approach was calm and laid back - very much 'Que sera sera'. "The team know me very well. If there's business going on behind it, I can't really influence it. But I'm standing here as a driver ready to race." Although Force India weren't saying it was a shoot-out - Sutil vs Jules Bianchi. It was definitely a shoot-out. A lot of it hinges on which engine they'll take next year, stick with Mercedes (favouring Sutil) or change to Ferrari (Bianchi).
We were introduced to the new Williams FW35 which, like the Caterham, had a contentious vane channeling exhaust gasses. Photo-copying king and technical director Mike Coughlan was adamant that whereas the Caterham version might not be seen as legal, the Williams one was. He also poured scorn on the other teams for taking too many variables to Jerez (where Williams had opted to take the old car). "I'm sure that a lot of teams went to Jerez with a new car, new driver and new tyres and got lost. We didn't."
Given what Jenson Button has said about the lack of complexity of the new Pirelli tyres, then the Williams team's move might be seen as a mistake. Setting up a baseline with the old car isn't going to be as important as seeing how the new car works with rapidly-graining but predictable tyres. Sergio Perez's comments add weight to this - he said that however you drove didn't seem to affect the tyre degradation, so the way the car was set up was key to the degradation. Williams missed four days of this (five if you include Barcelona's rainy Friday).
Fernando Alonso returned to action and his winter fitness programme was tested out by 110 laps of running on the first day. By the third day on Thursday he was emulating Felipe Massa (Jerez) and setting the fastest time. So what does he think of the new F138: "The feeling with the car was OK, all as expected, a continuation of the Brazil car let's say." He didn't seem overwhelmed, just relieved. "This is a good thing, not like last year when we drove for the first time and were a little bit surprised on the bad side."