AlphaTauri's Dany Kvyat will receive a five-spot grid penalty for Sunday's British Grand Prix as a result of a gearbox change on his car.
AlphaTauri diagnosed an issue with Kvyat's gearbox after the Hungarian Grand Prix, the Russian using a 'Friday' gearbox in yesterday's opening day of running but taking on a new transmission ahead of Saturday's practice.
Pierre Gasly who retired in Hungary with a gearbox failure will also receive a new element, but because the Frenchman did not finish the race at the Hungaroring, he will incur no penalty for the change
Gasly concluded Friday P8 in FP2 but Kvyat's efforts were disrupted by the untimely crash of Alex Albon and the red flag period that followed.
"I think it was a productive day, even if the red flag compromised my session a bit when I was on my new tyre run," said the Russian.
"I had to abort my lap and go again with the used tyres, so that was a bit unfortunate.
"Other than that, I think we worked on a good number of things and I was also quite pleased with the balance of the car today, so we have to analyse everything tonight and see what we can do to improve more tomorrow."
On the other side of the AlphaTauri garage, Gasly sought overnight improvements to boost his performance.
"It feels great to be back in Silverstone, which I think is one of the best tracks of the season and overall it was a good start to the weekend for us with many laps and tests completed," he said.
"However, I still don’t feel like I got the car exactly where I want it to be, so I’m confident that if we manage to make the right improvements overnight there’s a bit more performance to come for tomorrow."