As "experiments" with the W13 take Mercedes backwards, Lewis Hamilton anticipates a tough weekend ahead.

Lewis Hamilton's opening day in Hungary was best summed up in the moment when he asked the gap to the Ferrari. When informed it was 1.9s, the seven-time champ was clearly incredulous. "1.9 on the same tyre?" he replied.

Fact is, the W13's performance doesn't merely change from circuit-to-circuit, sometimes it's day-to-day, session-to-session, and Hamilton is as confused as the rest of us.

"The car is a bit of a struggle," he admitted at the end of a day on which he finished 11th on the timesheets, 1.102s off the pace.

"It's crazy how it swings so much from track to track," he added. "I'm just keeping my head up, trying to figure out how we can get the car working at the moment. It's a little bit loose and not doing what we want it to do. So yeah, a difficult day.

"Nothing has changed on the car since last week," he confirmed. "I'm the same driver this week as I was last week. But for some reason, this track, it's not working as well.

"It's going to be a tough weekend, that's for sure," he admitted, "but we'll give it everything and see what we've got."

"We came in sort of wanting to do some experiments with the car," admitted trackside engineering director, Andrew Shovlin, "and I think the ones that we did in FP2 with both drivers have taken us backwards.

"The first session we looked a bit stronger, the car was more together. There's a couple of things that I'm pretty certain we are going to be undoing overnight, because it didn't look great."

Check out our Friday gallery from the Hungaroring here.