Sainz still not satisfied due to "underlying balance issues"

Carlos Sainz Jr. set the fastest time on Wednesday's day of testing in Barcelona, but the McLaren man isn't completely satisfied with its MCL34 - saying there are "underlying balance issues".

Sainz recorded a 1:17.144 in the morning session of Day Six of testing, and nobody could trump that or get anywhere near his time.

However, the Spaniard was not fully pleased as he headed back to the pitlane in Barcelona. He admitted there has been a gradual improvement in its car but there is still some real work to do before the first race of the season in Australia.

"There are still big areas of improvement needed, definitely," Sainz admitted. "The important stuff to come out of testing is that every time I go out on track, I think the car has been progressing.