Carlos Sainz suffers 'shock' despite positive Williams step

Carlos Sainz suffered a "shock" on the opening day of track action ahead of this weekend’s Japanese Grand Prix, despite Williams making a genuine step forward.

The Spaniard ended Friday 13th on the timesheets, but less than two-tenths adrift of Audi’s Nico Hülkenberg in seventh.

Williams’ one-lap pace was highly encouraging for the Grove-based outfit, with Alex Albon getting himself into the top 10.

Over one lap, progress does appear to have been made, offering fresh hope for qualifying. Unfortunately, similar gains have not been made on high fuel.

The pace drop of his car shocked Sainz, to the extent that he questioned whether it was even worse than what he experienced in the previous round in Shanghai.

He has called for the team to "analyse" what is causing such a significant performance difference between low- and high-fuel runs, but still judged it to have been a positive day.

"We’re trying things, and definitely today it seemed like, at least on low fuel and short runs, we were able to mix it up in the midfield," said Sainz.

"Unfortunately, when we moved to high fuel, it was a bit of a shock how much of a step backwards we took.

"So I think, as a team, we need to analyse what’s making us more competitive on low fuel this weekend, and then what’s bringing us back to our China level on high fuel, or even worse.

"So there are some good and bad aspects. Maybe a bit more good than bad. In the end, it’s a good sign that we could at least mix it up on low fuel."