https://twitter.com/hlawiczka/status/969484656713322499
https://pbs.twimg.com/media/DXRM8d0WkAAQW9c.jpg
F1 1st week of pre-season testing in Barcelona: Who's improved most over the year (1st week of pre-season testing 2017 vs 1st week of 2018):

1. McLaren -2.722s (used hyper-soft instead of ultra-soft, changed engine from Honda to Renault)
2, Haas (same compound)
.
10. Sauber