Yamaha's Jorge Lorenzo finished the final day of the private Aragon test ahead of title rival Dani Pedrosa, although the Honda rider's Tuesday time remained unbeaten.
Lorenzo spent the first of the two days testing chassis settings and day two a different engine specification along with general bike settings to prepare for the Aragon Grand Prix later in the month.
The 2010 world champion completed 77 laps on Wednesday, the best of which - according to Yamaha - was a 1m 48.351s, although both Honda and the Aragon circuit state that Lorenzo's best was a 1m 48.244s.
A picture on the Yamaha MotoGP Twitter feed also seems to confirm the 1m 48.244s time.
Either way, Lorenzo was between 0.148 and 0.255s clear of Pedrosa on Wednesday. However Pedrosa's 1m 47.983s day one time was unthreatened.
It was not disclosed if Lorenzo, who wrapped up the test with a race simulation run, intends to use the new chassis or engine at the forthcoming Misano (September 14-16) or Aragon (September 28-30) rounds.
"Today was a very long day, we made a race simulation at the end of the session so I feel very tired but it was necessary to see the performance of the rear tyre," said Lorenzo.
"In general we leave here with happiness and confidence as we've been one second faster than last time [during the June test]. We need to try and improve consistency over race distance here."
Honda LCR rider Stefan Bradl was third quickest with a 1m 48.834s, followed by Lorenzo's team-mate Ben Spies (1m 48.946s) and Pedrosa's temporary team-mate Jonathan Rea (1m 50.057s).
Lorenzo holds a 13-point title lead over Pedrosa with six rounds to go.