Unbeaten McLaren holds off on new car.

Despite knowing that world championship rivals Ferrari will enter at least one of its new F2003-GA chassis in next weekend's San Marino Grand Prix, McLaren has opted to further delay the launch of the car that it hopes will continue its stirring start to the season.

The current MP4-17D has won each of the opening three rounds - pending tomorrow [Friday]'s FIA enquiry into the official time-keeping at Interlagos - giving McLaren a healthy advantage at the head of both drivers' and constructors' championship tables. Ferrari, however, is still reputed to have the outright fastest car and, with the debut of the F2003-GA slated for Imola, may suddenly begin to cut into the Woking team's lead.

However, despite the obvious risk of not meeting fire with fire, McLaren looks set to delay the launch of the 'radical' MP4-18 until at least the Austrian GP in late May. The car has yet to turn a wheel in anger and a maiden test, slated for this week, has now been shelved.

"A low-key launch of the car [will take place] within the next month and the first test will follow shortly after that," a team spokeswoman told BBC Online.