The 2020 world champion said Honda “needed a bit more help” after September’s Misano test, at which Marc Marquez admitted the team was “still far” from where it needed to be.
But speaking after Tuesday’s test, Mir was visibly pleased with the progress made, and said the bike “seems to be working better.”
He also revealed it was the "first time I have been able to feel a difference since I arrived" for the 2023 season as Suzuki bowed out of MotoGP.
Mir remarked: "I'm quite happy, it's the first time in a test that they really brought something that worked.
"I felt pretty good all day, it was a challenge, on Friday after the crash I thought I wasn't going to be able to do the test.
"It was hard to improve a little bit every day and it was difficult to get the feeling after not riding during the weekend.
"But I quickly got into the lap times and this bike seems to be working better. We had a very good rhythm in all the rides we did, every time we went out it improved.
"We tried a lot of things and we didn't have time to put the soft tyres on to attack the time, but I'm very happy. The potential is different."
Source: Autosport