A productive day at the Circuit of The Americas, which was spent evaluating and comparing various aero components on both sides of the garage, and progressively adapting to the changing track conditions as the surface rubbered in.
Both drivers spent much of the first session dialing in the set-up of the MP4-31 to the circuit's steep gradients and increasing track temperatures. Jenson concluded his running a couple of laps early for precautionary checks after an anomaly was detected in the power unit. The issue was quickly resolved by a sensor change and didn't affect any of the rest of the day's running.
By the latter half of the second session, both drivers reported that the balance had improved, and were able to commence high-fuel running in preparation for Sunday's race. A temporary halt was brought to proceedings on only their out-lap, when the red flag stopped the session to clear debris on track. It was restarted shortly after and Jenson and Fernando were able to conclude their respective programmes successfully and without any issues.
Fernando Alonso: "It was a good day in the office. We completed our programme and were able to put a good number of laps under our belt, which was very helpful.
"In the second session we also tried the different compounds and we will need to choose carefully, because the Supersoft seems to have quite a lot of degradation, as we expected. We'll make our decision once we have gone through all the data we gathered today.
"We tested several items, aero parts and mechanical settings, and some things went better in FP1 and some in FP2, so we have some work ahead of us to be ready for tomorrow."
Jenson Button: "Today wasn't too bad. I really enjoy driving around here but there's definitely still some more work to do. This track is always tough on tyres as there's high degradation, but it's the same for all of us, so I think we'll be okay.
"The mid- and high-speed corners are always a challenge for us and the long Turn 17 is tough, especially on tyre wear. A few cars have been hitting the orange kerb in Turns Three, Four and Five, and it's been breaking off parts of the floor, but luckily we haven't had any issues on our car.
"When we bring a Supersoft compound to a circuit where we're not used to running it, there's degradation, but it's pretty normal and we haven't found it too bad. There's degradation on all the compounds - even the Medium tyre overheats pretty quickly and isn't as consistent as you would like it – so this circuit is definitely tough on tyres, but that's part of what makes it interesting."
Eric Boullier, Racing Director: "Today we ran through all our planned programmes efficiently and successfully, emerging at the end of the FP2 an encouraging eighth- and ninth-fastest.
"The track temperature was surprisingly low for FP1 this morning, but it had warmed considerably for FP2 this afternoon. That, and the set-up work we'd done between the sessions, led to both drivers reporting good handling balance by the time they'd completed their high-fuel runs at the end of the day."
Yusuke Hasegawa, Honda R&D Co Ltd Head of F1 Project & Executive Chief Engineer: "Today's free practice ran smoothly, with the team performing many aero and mechanical tests and engine mode confirmations fitting to the circuit. At the end of FP1, one of the sensors on Jenson's engine dropped, but it did not affect the run plan, and was a simple fix of parts to prepare for FP2.
"In the afternoon sun, the track conditions became more ideal for longer runs and tyre testing, so both sessions were very busy today. We haven't found the perfect balance in the package yet, but we were able to gather tons of data to analyse and prepare for tomorrow's qualifying."
Check out our Friday gallery from Austin, here.