Ferrari secretive in Formula One testing

Red Bull's Sebastian Vettel was quickest in Formula One pre-season testing today but much of the session was again disrupted by rain.

The German clocked a best lap of 1 minute 22.593 in an eventful day in Spain where new team Lotus started testing and Ferrari used elaborate means to keep improvements to the back end of Felipe Massa's car covered up.

The Italian team first hid the diffuser behind panels and then put a huge black bag over the back when the Brazilian, who posted the third fastest time, was among a number of drivers to grind to a halt on the track.

The Lotus brand returned to full testing for the first time in 16 years with reserve driver Fairuz Fauzy.

"76 laps. Great day well done Fairuz. Great day for Lotus. Great day to see a British brand back in action. Great day for Malaysia," team principal Tony Fernandes told Twitter.

Teams had trouble with the weather at last week's test, also held at Jerez, and the forecast is little better for the remaining three days of the session.

The last test is in Barcelona next week before the season-opening race in Bahrain on March 14.

Testing is only allowed in the limited official sessions, frustrating teams who are already struggling to judge how competitive they are given rivals have different fuel loads.

Refuelling during races is banned this season.