Bridgestone, the sport's official tyre maker, has brought three new versions of the slicks to the Circuit de Catalunya, following teams' concerns that the earlier developments were extremely difficult to get heat into -- resulting in huge and dangerous speed differentials between circulating cars.

The massive lap time difference between Felipe Massa and the rest of the field as the test opened on Monday, however, was for a different reason.

While the Brazilian tried the slicks late in the day, his F2008 was equipped with this year's aerodynamic configuration, resulting in a lap record that was nearly three seconds faster than the closest challenger.

Other teams, like McLaren, were trying the slicks in conjunction with simulated 2009 levels of downforce, including a flat rear wing that significantly reduced cornering speeds.