1 Mercedes are still the class act of the circus

The three pre-season testing sessions are Formula One’s big sandbagging festivals of the year. However, the double world champions just couldn’t conceal the fact that they are still the class of the field. They pounded in the laps (all 515 of them) like Haile Gebrselassie but it was all done in a mooching style that suggested there was plenty more to come, and they were still quick enough, even running medium rubber. The second heaviest lappers among the big four were Ferrari, with 349. Mercedes went to Spain ahead of the rest and learned more than any other team.

2 Ferrari have made a big step forward

Some say the prancing horse could be the dark horse of the 2015 F1 championship. OK, they appeared to be showboating as they dominated the timesheets in Spain – they and the Ferrari-powered Sauber were first and second in terms of pace on all four days. But it is worth noting that Nico Rosberg described Ferrari’s pace as an “eye-opener”. Much more important is that both drivers, Sebastian Vettel and Kimi Raikkonen, seemed happy with the car, and did plenty of laps too.

3 McLaren have much to do before Australia

McLaren hit the ground spluttering but completed so few laps, only 79, that we will have to wait until the next two tests in Barcelona before we can make a more qualified judgment. The car looks great – but the Honda power was missing. The McLaren chairman, Ron Dennis, promises a much-improved engine for next time out but this once great partnership is likely to be playing catch-up in the opening races of the new season. In Jerez they looked the prettiest back-marker in F1.

4 Red Bull still have Renault problems

Red Bull came in disguise, with a livery designed to camouflage some of their new bits. But their performances would have done the job instead. Was this really a Red Bull? Only McLaren did fewer laps and the worry is the same as in 2014 – is that Renault engine any good? On this evidence, not good enough.

Kimi Raikkonen of Finland drove impressively in Jerez. Photograph: Mark Thompson/Getty Images

5 Kimi Raikkonen rides again for Ferrari

Forget the fact that he put in the quickest lap of the four days. The point is that Raikkonen, who never gives anything away, appeared to have a real spring in his step after a wretchedly disappointing season with Ferrari last year. “This year is completely different,” he enthused. That could make life very interesting for race fans, because after his own disappointing season with Red Bull last year Sebastian Vettel has something to prove, and he can only do that by blowing Raikkonen away.

6 The cars will be quicker than in 2014

Last season started in Australia with some complaining about the poor sound coming from the smaller engines. Some idiots even wanted the noise artificially enhanced. In fact most people had been won over by the end of the year. The good news from Jerez is that the cars will be lapping more quickly this year. The fastest lap in Spain was Kimi Raikkonen’s 1min 20.841sec. That was quite an improvement on Kevin Magnussen’s 1:23.276 last year.

7 Williams will be very strong again

The success of Williams in taking on and often beating the big teams of Formula One was one of the most rewarding factors of last year. They were, arguably, the team of the season. Williams, still with Felipe Massa and Valtteri Bottas, did not catch the eye in Jerez – for good reasons or bad. They were just their old solid selves but they have certainly made enough progress to suggest that they did not peak in 2014. They have added needed downforce and Pat Symonds, the chief technical officer, looks happy.

8 McLaren were right to hold on to Jenson Button

The humiliation suffered by Jenson Button in having to wait until the end of the year before having his contract renewed dented the reputation of the McLaren chairman, Dennis. But at least he came up with the right solution, eventually. Button’s patient smile was a reminder that McLaren have just the right man aboard. The 2009 world champion’s vast experience will be vital in shaping the difficult immediate future of the new McLaren.

9 Lewis Hamilton will not be left out of the picture

The double world champion is often fast and brilliant. When he fails, he often does so spectacularly. That’s what makes him the most compelling figure in the sport. Team-mate Nico Rosberg had the more successful time in Jerez, completing 100 more laps. But Hamilton, spinning off the track on the final day and breaking up with his girlfriend, stole the German’s thunder once again.

10 We have learned how little we know

The oily rag rubbed his chin with weary boredom. “We won’t really know how good we are – how good anyone is – until Saturday and qualifying in Melbourne on 15 March,” he said. It’s the same message we hear every year, especially after the first testing session. Every team came here with different issues to overcome. They didn’t come to put on a show. But it was still rather worrying for two of the biggest rollers in town, Red Bull and McLaren.