Rivals fear Ferrari's new F2003-GA

"I don't know how quick the car is," Montoya said. "It seems to be a bit quicker than the old one but this year they haven't been that quick around Barcelona. We tested with them and they might have had quite a lot of fuel but we were quite a bit quicker than them."

Ferrari technical director Ross Brawn confirmed that reliability rather than performance issues had delayed the new car. "We were confident performance-wise that it was a step forward but had a couple of unexpected testing problems," he explained.

"The old car was still competitive and if it hadn't have been, maybe we'd have made a different judgement call. We did over 3000kms at Mugello last week and so we are as confident as we can be, but you only start to understand a car more when you go racing with it."

Ferrari steamrollered last year's Spanish GP, with Michael Schumacher almost a full second faster than anyone bar team mate Rubens Barrichello in qualifying, and 35s clear of Montoya at the chequered flag. Brawn, however, said in Spain: "I had a look at last year's race on the TV and I don't think we'll have it as straightforward as that. I think we will see different phases of the races because of the differing tyre characteristics between Michelin and Bridgestone."

Patrick Head, however, was candid about the Williams chances. "I think our performance is certainly stronger than was shown by our finishing position at Imola," he said, "but still, I'm sure it isn't going to be strong enough to deal with Ross's new car."