The team broke with Formula One tradition by launching the R4 on the internet.

And new drivers Mark Webber and Antonio Pizzonia were cautiously optimistic about their prospects.

We focused on everything to ensure we contest the season with a car that is capable of being competitive and finishing races reliably Jaguar boss David Pitchforth

The R4 is due to run on a Grand Prix track for the first time on Tuesday at Barcelona's Circuit de Catalunya after being straight-line tested in Belgium last week.

"I'm not going to get out my crystal ball and start making predictions but I want to go racing, let's put it that way," said Webber.

"Last year at Minardi I was in a team that, largely through no fault of its own, was stuck at or near the back throughout the season.

"I'm not saying were going to be challenging the big boys in 2003, but I'm certainly hoping we'll be serious players in that tight competitive bunch immediately behind them."

Jaguar, who are owned by Ford, joined F1 in 2000 when they took over the Stewart team.

Jaguar drivers Antonio Pizzonia and Mark Webber

They finished seventh in the constructors' championship last season, with team boss Niki Lauda and drivers Eddie Irvine and Pedro de la Rosa all paying for the poor return with their jobs.

Brazilian Pizzonia was test driver for Williams before joining Jaguar and has yet to drive in a Grand Prix.

But the 22-year-old insisted he was ready to make an immediate impact in 2003.

"I tend to learn circuits pretty quickly, so I'm not too worried. And I quite like the changes in the regulations," he said.

Jaguar's managing director David Pitchforth insisted lessons had been learned from the poor performance of the R3 car in 2002.

"We focused on absolutely everything to ensure that we contest the season with a car that is capable of being competitive and finishing races reliably," said Pitchforth.

"It sounds obvious, I know, but that's not how Jaguar Racing began last season and by the time we had worked out the problems with R3, most of the season had passed us by."