Toyota's new car is eating its tyres far too quickly

Trulli told Italian newspaper Gazzetta dello Sport the car was using up its tyres too quickly, damaging its ability to keep its pace over a race distance.

"The car seems quick and competitive, but not over the distance," he said.

"The problem is excessive rear tyre wear; we have three weeks left (before the cars are sent to Australia for the first race) and we hope to resolve it."

Toyota are substantially to change the car's aerodynamics before the car hits the track in Melbourne, but Trulli said the team did not know what was causing the problem.

After three laps, the car becomes more difficult to drive Jarno Trulli

It would be particularly damaging this season if it was not solved, as new rules ban tyre changes - teams must use a single set of tyres for qualifying and race.

Trulli said the problem reminded him of a similar characteristic that afflicted his Jordan car in 2000 and 2001 - a machine that was designed under the leadership of Mike Gascoyne, now Toyota's technical director.

"It's definitely not the weight distribution," Trulli said, "but we still haven't worked out whether it is an aerodynamic problem or mechanical.

"After three laps, the car becomes more difficult to drive, and in that it reminds me of my old Jordan.