Pramac Ducati's Jack Miller branded the Desmosedici GP19 as 'crazy' following two days of MotoGP testing at Valencia.

The Australian stepped off a GP17 on Sunday night and on to the new works machine come Tuesday morning and said it was night and day different.

"I cannot believe the bike is from the same family. Everything's new, the gearbox, down to the handlebars, how the handlebars feel. It's hard to almost believe it's only two years more advanced than my bike, but the amount of changes are crazy. It's better at everything. Turn, brake, stop, accelerate, be smooth," said Miller, speaking at the track.

"It feels easier. Definitely. That was the biggest thing, I came in and I said it feels very light, very easy, especially through the first change of directions here, from 8, 9, 10, 11.

“Even though there were still wet patches and I was trying to stay well away from the white lines, I found myself almost turning onto the white lines on the inside because of how well it was turning.”