LONDON, England - Mercedes' Michael Schumacher has criticised Pirelli's Formula 1 tyres by saying they make him feel like he is driving on raw eggs.The seven-times World champion, who has not stood on the podium since he began his comeback in 2010, told CNN in an interview that the Italian tyres were having too much of an effect on racing.'LIKE ON RAW EGGS'"They are so peaky and so special that we don't put the cars or ourselves to the limit," he said ahead of this week's 2012 Spanish GP in Barcelona, the start of the European season after four long-haul races."We drive like on raw eggs and don't want to stress the tyres at all. Otherwise you just overdo it and then you go nowhere," said the 43-year-old German, who won his titles with Benetton and Ferrari.Pirelli replaced Japanese brand Bridgestone as the only tyre-supplier at the end of the 2010 season and has been credited with livening the racing with tyres that are less hard-wearing.Schumacher, whose team mate and compatriot Nico Rosberg won the 2012 Chinese GP in April - the first victory by a Mercedes works team driver since 1955 - also criticised the tyres after the 2012 Bahrain GP.'HE WAS VERY HAPPY'Schumacher had complained then that drivers could not push their cars to the limit because of the need to save the tyres. Pirelli responded to that criticism with "disappointment" and pointed out that the former Ferrari driver had seemed happy enough before the season started."Others were getting on with the job and getting their tyres to work," motorsport director Paul Hembery said. "His comments during winter testing were that he was very happy with the tyres; now he seems to have changed his tune."