Dani Pedrosa was quickest as the Repsol Honda team dominated the first day of post-season testing in Valencia.
Pedrosa and world champion Casey Stoner were more than a second a lap quicker than the rest of the field as they tested their new 1000cc bike for 2012.
A change in rules means the bikes will have bigger engines next season.
British rider Cal Crutchlow was fifth on his Tech 3 Yamaha, ahead of multiple world champion Valentino Rossi, who was sixth on the new Ducati.
Stoner said: "In general it was good to be out there on the 1000 and feel the horsepower, it's a lot of fun and I'm looking forward to feeling it on a lot of different tracks."
Yamaha rider Jorge Lorenzo missed the test as he recovers from while Rossi's team-mate Nicky Hayden was forced to miss out after discovering he broke his wrist in the first-corner accident in Sunday's final race of the season.
New Moto2 champion Stefan Bradl had his first experience of a MotoGP bike as he tested the 800cc LCR Honda.
Valencia test times:
1) Dani Pedrosa (Spa) Repsol Honda 1min 32.186 secs
2) Casey Stoner (Aus) Repsol Honda 1:32.322
3) Ben Spies (US) Yamaha 1:33.226
4) Randy De Puniet (Fra) Suzuki 1:33.544
5) Cal Crutchlow (GB) Tech 3 Yamaha 1:33.652
6) Valentino Rossi (Ita) Ducati 1:33.857