Toyota plan revised car for Monaco

Toyota were the first of the 10 teams to get their new V8-powered car on the test track in November and Gascoyne said that the TF106 version would be replaced by a TF106B after the first six races.

"It's a measure of the pace that you need to develop," he told reporters at a pre-season event in a Toyota car factory in northern France at the weekend.

"It's very blurred what defines a new car now. Toyota are proving that, in that it's constant update. The designation 106 or 107 is just a year designation for convenience sake, it really is a process of constant evolution and development."

Gascoyne said the car that will start the season in Bahrain on March 12th was a marked improvement on its predecessors and early testing of it had allowed Toyota to make further developments.

The team decided late last season to switch from Michelin tyres to Bridgestone for 2006.

"If we'd rolled out a new car for January, we still couldn't have incorporated any of the things we'd learned from testing Bridgestones in November," said Gascoyne.

"We can now react and introduce the TF106B bearing in mind all that we've learned from testing".

Gascoyne said the rear end of this year's car boasted a very different rear suspension layout to last year's.

Toyota finished last season fourth overall, their best performance since they entered the sport in 2002, and are aiming for their first race win this year.