Ralf Schumacher has launched a blistering attack on his former team Williams, claiming that they are far from being a top outfit.
The 29-year-old, who spent six years at Williams before moving to Toyota for this season, says expectation levels at his ex-employers were not justified.
"I did not know I was driving for a top team. It did not seem that way when I was there," he told a German newspaper.
"The high expectation levels at BMW Williams were totally unrealistic."
Germany's Nick Heidfeld and Australian Mark Webber will drive for Williams when the season starts in Melbourne on 6 March but Schumacher does not believe they can challenge for the title.
"Apart from the engine there was not much quality there and the optimism could not be justified," said Schumacher.
"I do not think BMW Williams have a championship winning car this season."