In a comparison to last year's testing on the Circuit de Catalunya,
McLaren are the team that have shaved the most time off their 2017 benchmark. On the other side of the spectrum,
Williams are the least improved team, only improving by two decimals compared to McLaren's 3.5 seconds.
We know that you can't take too much away from pre-season training in terms of pecking order by looking at just the lap times. Mercedes ended as the seventh team this year, but everyone still knows that they're still the favourites to win it all again this season.
It does give an impression of where all the teams are at though. Last year, McLaren were clearly at the dawn of a horrible year, with Alonso looking the most sad and frustrating we've ever seen him.
This year, it's a different story. McLaren are the most improved team with a whopping 3.5 second improvement compared to last year. Alonso landed the third best time of testing with his 1:17.784, only beaten by both Ferrari's. Compare this to last year, when Alonso had the 17th best time (1:21.348). On top of this, while reliability is still the main issue, the papaya-orange car looks quick. The vibe that comes out of the paddock is so different, so much better.
Sauber, last year's last-placed team, were the second-most improved team, shaving off 2.5 seconds in a year. The worst two teams of last year were obviously the ones that had most room for improvement, so it's not as surprising to see Sauber and McLaren top the list.
At the bottom of the list, we find Williams, just improving by 0.2 seconds. And it's not like they had such a good season that there was barely anything to improve. What has to be said in defence of the British team though, is that they were the only ones (with Haas and Mercedes) who didn't test in the new, faster, hypersoft compound. Still, not a good sign heading into the 2018 season.