MONTMELO, Spain -- Robert Kubica has warned against making comparisons between his and Williams rookie Sergey Siriotkin's times over winter testing.
Williams picked Sirotkin over Kubica as its second race driver for 2018, but retained the Pole in a development role for the season which will include some test appearances and three Friday practice sessions. Both drivers appeared in the car on Tuesday and Kubica's best time was 0.3s quicker than the Russian's.
Sirotkin propelled himself into race seat contention at the post-season Abu Dhabi test last year, where he and Kubica were evaluated simultaneously. Kubica was quick to point out the comparisons are different now the two men have very different roles to prepare for.