The first four days at Barcelona had an unusual level of drama with sick notes, spins, crashes and an ominous final fling from Mercedes.
* With both Mercedes drivers in attendance for the Silver Arrows at the Circuit de Catalunya, reserve driver Pascal Wehrlein was very surprised to get a call on Thursday saying he was needed. Especially seeing as he was already ten laps into a test for Force India. However with Lewis Hamilton running a fever and getting out of the car, and Nico Rosberg needing work on a trapped nerve in his back, the DTM driver suddenly found himself in a Mercedes W06. And achieving a rare feat of appearing twice on the timesheets!
* Lewis Hamilton had a frustrating time with the 2015 Pirelli rubber at Barcelona. Although Pirelli brought along a tyre badged as a 'winter hard' especially for the colder conditions Hamilton wasn't impressed with the medium either finding it hard to get into the operating window: "They don't work. Then one lap you might feel it is not so bad, but then it drops off. I ran the hard yesterday and it was even harder. My first impression of the tyres is not spectacular, but maybe when we get to hotter conditions it will be better."
* The unpredictability of grip from the tyres was responsible for many unexpected spins into the gravel including Hamilton, Nico Rosberg and Sebastian Vettel.
* The McLaren-Honda partnership continued its miserable start with only 124 laps across the four days – less than many teams put in a single day. Fernando Alonso’s final day spin and crash that prompted a precautionary airlift to the hospital was the lowest point of the four days.
* 'Honda Happiness' disappeared when the seal on Jenson Button’s MGU-K unit failed on Day One, necessitating the engine manufacturer to hastily re-design and re-engineer the part and fly it out for Saturday. And then the redesigned part failed. Although McLaren are keen to stress the heritage of their relationship with Honda, by flying out an MP4-4 and displaying it at Barcelona, this Honda looks more like the ‘Earth Dreams Honda’ than the 1980s turbo Honda.
* Ferrari boss Maurizio Arrivabene was keen to big up the ‘new’ happy Kimi Raikkonen. "He is demonstrating that these days, he is feeling the (turn in of the) car better and he is smiling. This is very, very strange. It is the real scoop of the weekend."
* Romain Grosjean claimed the fastest time on the final day with a glory run on SuperSoft Pirelli tyres. His 1:24.067 put the Lotus on top for the second day running after team-mate Pastor Malsonado claimed top spot on Day Three and also on Day One. The Frenchman’s time was fastest of the week and showed that Lotus will be contenders again this season.
* The most ominous time was put in by Nico Rosberg on the final afternoon with the Mercedes just 0.254 seconds behind the Lotus. Nico’s time was set on the Medium tyre which Pirelli estimate was 1.5 to 2 seconds slower than the SuperSoft. Sebastian Vettel’s fastest on the equivalent tyre was over two seconds slower.
* The Mercedes stats juggernaut continued with the team putting in most laps – 446 compared to 418 for Red Bull and 411 for Toro Rosso. Williams put in 407 laps, a total that would have been higher had Susie Wolff and Felipe Nasr (Sauber) not had a coming together on Day One.
* Force India were the only team running last year’s car, the VJM-07. Their test was focused on finding out how to get the best of Pirelli’s 2015 rubber, with a known quantity. Nico Hulkenberg suffered an engine failure on the final day that cut their running to just 36 laps.