Lando Norris: "The tarmac and temperatures here make it quite tricky to get everything in the right window, which makes the car balance quite tricky as well. It's been very difficult to put a lap together, due to the disrupted sessions with the red flags and traffic at such a short circuit. Those factors, in combination, have made it a very difficult day to achieve a good balance.
"We ended up in a good position, but I think we're a long way from that in terms of actual pace. So, we've got a lot of work to do tonight to see how we can improve for tomorrow."
Carlos Sainz: "I think it's been a challenging Friday out there, for everyone. A track with very low grip, and the wind picking up in the afternoon made things even more tricky.
"We managed to finish the session fairly high up on the standings without particularly clean runs or clean laps. That means everyone has a very large margin for improvement going into Saturday. We still need to improve the car quite a bit overnight and make sure we get it in the right window for tomorrow."
James Key, Technical Director: "It's nice to come to another new circuit. Portimao is a great track and a genuine technical challenge with the variations of corner type and elevation, so there's been a lot to learn today. We've been able to do our homework, including the running we did for the Pirelli tyre test, which added some useful laps for everyone.
"We had some test items on the car today and we'll have to analyse the data from those this evening, but early indications are positive. The car seemed reasonably stable and well set-up from the start, despite the difficult grip conditions, which is a credit to the work put in by the race team here and the various groups back at the factory. There's still work to do overnight and tomorrow morning but, overall, it's been a productive and useful day."
Check out our Friday gallery from Portimao, here.