Carlos Sainz knows the process of moving Williams up the Formula One grid will take some time, but the 30-year-old Spaniard said his motivation to do so is "unbelievable."
Sainz jumped in his Williams car for end-of-season testing on Tuesday, and posted the second-fastest time behind Charles Leclerc as teams tinkered with setups and run plans.
Sainz and Leclerc were teammates for the past four years at Ferrari and helped the team claim second place in this year's constructors' standings.
With your current subscription plan you can comment on stories. However, before writing your first comment, please create a display name in the Profile section of your subscriber account page.