MotoGP world champion Jorge Lorenzo finished Friday practice for the French Grand Prix in fourth place and with 'a lot of margin for improvement'.

Lap times were close at Le Mans, with Lorenzo a mere 0.166s from fastest man Dani Pedrosa.

Squeezed between them were Marc Marquez and Valentino Rossi, but if the forecast rains arrives Friday's form could count for little.

"We are changing the bike to improve the feeling because at the moment we have a lot of margin for improvement. I think we can make a big step to improve the constant pace for the race.

"I think if it rains tomorrow things will change completely and it will be a different story. We will have to be as always more careful and have more concentration in the wet."

Lorenzo won last year's wet Le mans race by almost ten seconds from Rossi.