Fresh from a bitter third place in Sunday's grand prix, MotoGP champion Lorenzo pounded out a massive 81 laps of the Jerez circuit during testing on Monday.

Lorenzo and team-mate Valentino Rossi spent most of the test trying to reach a decision on which chassis specification to stick with, whilst also working to improve tyre performance in the hot conditions.

Lorenzo, who lost second place in his home event after a clash with Repsol Honda rookie Marc Marquez at the final turn, set the third fastest lap at the test - just 0.134s behind pace setter and title leader Marquez.

"It's been a long day, it was not easy to finish the day on the bike because after three days full of stress of competition the only thing you want is to rest," said Lorenzo. "I think the work was worth it because we improved some things. We tried many starts and finally I found again the same feeling I had last year."

Two versions of the M1 frame have been available since winter testing and Lorenzo 'thinks' he will use the newest from now on: "I think we also improved the bike and I think we decided the new chassis so it has been a positive day."

But Rossi is far from certain, and will make a decision in the coming days. The Italian, a lonely fourth in Sunday's race and openly disappointed by the gap to both Lorenzo and the Repsol Hondas, was fifth quickest at the test (+0.573s).

"It was important to try to understand the new chassis," said Rossi. "We made a lot of comparisons between the two but at the end more or less the performance is very similar. In some places it's better and some places it's worse. We will decide next week what we will use in Le Mans but I think we will continue with the normal chassis."

The Italian added: "At the end it has been a good test. It was important because we found some improvements in some points of view, small details but a good way to continue," he said.

"We are ready for Le Mans, now we take a rest and we will see next week."