Jorge Lorenzo believes Yamaha has made big steps with the performance of its 2009 factory YZR-M1.
The Spaniard got his first proper chance to test the prototype M1 in Jerez and the double world 250 champion ended with the third best time.
Lorenzo, who finished fourth in his rookie premier class campaign, posted a best time of 1.40.426, but he was still 0.997s slower than Fiat Yamaha team-mate Valentino Rossi.
Lorenzo, who was also third quickest on the opening day, said: “Today we concentrated on the evolution bike, which has some prototype parts, with a new setting from Valentino.
"It seems we had a small advantage with this bike and I was able to improve my time, so I am happy about this. This ‘new’ bike is also more stable under acceleration, with less wheelie and the throttle is a bit easier to handle so these are important improvements.
"The final conclusion of these two days is very positive I think, although we know there is still a lot of margin to improve, both in the bike and in my riding style and of course we need to keep working to better understand the new tyres.”