Lewis Hamilton was upbeat about Mercedes chances at Mexico, claiming the car has got "better and better" as the team has done more work to understand the W13.
The team ran their controversial new front wing at the Autodromo Hermanos Rodriguez, however they had to make a modification by getting rid of the turning vanes from the flap separators for it to comply with the regulations.
Speaking about the session to media, Hamilton said he feels good about the performance of the W13 after going fifth quickest in FP1 and fourth fastest in FP2.
"I had a good session today, so generally feel good about our performance so far," he said.
"I really enjoyed driving around the track, because the car is feeling better and better as we learn to understand it in more detail.
"Of course, we will do plenty of work tonight, to see if we can compete with the front. But you never know with this car how the rest of the weekend will go, but I hope we are able to continue to build on our positive conclusion from today."
Speaking about the 2023 test tyres which were trialled by all teams in FP2, Hamilton believes they are similar to the current set of 18-inch Pirelli's but are a lot easier to stop from overheating during a long run.
He added: "The 2023 tyres seem very similar to the current ones, maybe a little bit more consistent on the long runs and easier to manage in terms of overheating."
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Shovlin: Car working well on single lap and long runs
A unique situation at the Autrodromo Hermanos Rodriguez could put Mercedes in the mix for a win.
The track is located 2,240 metres above sea level which gives it a much lower air density, and creates less drag for the cars in a straight line.
This is something that has hampered the W13 throughout the season, with its top speeds nowhere near that of the Red Bull RB18 or Ferrari F1-75. At Austin, Hamilton was 9.9 kph slower than the quickest recorded.
After both practice sessions, Mercedes Trackside Engineering Director, Andrew Shovlin, thinks the W13 is working well on both the single lap and longer runs.
"From what we can tell the car is working well on both single lap and long run," he explained.
"The balance isn't perfect, so we've got areas to work on overnight, but a reasonable start at what is normally a very challenging circuit."
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