Schumacher praises Stewart

But on the eve of the first practice day for the Brazilian Grand Prix he also warned that they needed to be just as competitive in development testing as well as the races if they wanted to remain contenders throughout the season.

'Last year wasn't so good for them and to make such a great step over the winter is significant and impressive,' said the double champion.

'They will be very good in Brazil and they will be good, probably, in Imola but I don't know how much they can keep up the pace with the further development during the season.'

'There are strong teams and weak teams. I don't really know their capacity. Maybe Stewart will be
the biggest challenger to the top two teams now and then it will change around to Jordan or Williams later,' he added.

Technical director Gary Anderson says the team has a comprehensive testing programme for the season that would 'blow most people's minds.'