A strong Friday for Williams at the British GP has Christian Horner wary of their impact come Sunday’s race.

Alex Albon was third fastest in opening practice, maintaining that place in the day’s second session.

Supporting that was Logan Sargeant, who was fifth fastest in Free Practice 2, just 0.4s away from his team leader.

“Super impressive, and not just Alex, both the guys,” Horner said on Sky Sports of Williams’ Friday performance.

“Proper, proper laps; not just one lap. I mean, their long runs look pretty sensible as well.

“Based on that pace, they would be a factor in the group behind.”

Williams has been showing improved form of late, with Albon racing his way into the points at the Canadian Grand Prix and then just missing out last week in Austria.

That uptick has coincided with the introduction of upgrades, initially to Albon’s car in Montreal before Sargeant had them on his FW45 at the Red Bull Ring.

This weekend, new front and rear wings have been introduced.

According to the team, the front wing change is designed to improve the airflow under the car, thus improving downforce, while the rear wing is less draggy than its predecessor.

Williams team boss James Vowles is more circumspect. While acknowledging the solid start to the Britsh GP weekend, he downplayed it.

“We look strong, but we were more focused on qualifying than others,” he said after Free Practice 1.

“Some teams didn’t even run the software we ran quite late on, so we’ll keep our feet on the ground at the moment.

“What I can say is, from Montreal onwards, we put an update in the car that allows us, if we get everything right, to score points.

“We didn’t get everything right in Austria, that’s the reality behind it, but we have the opportunity to be there or thereabouts.

“And I think the same applies to this weekend.

“What you’re seeing from the outset, it’s a positive start, but to give you an idea, Logan’s [Practice 1] lap wasn’t bad at all, just very early on and fell back as the track improvement ramped in and other people did their laps.

“The main thing is we’re learning with the package we’ve got and I’m really just doing the best we can by moving forward relative to a highly competitive group.”

Practice at Silverstone continues on Saturday with Free Practice 3 beginning at 11:30 local time (20:30 AEST).