McLaren was the least reliable team of the 2011 pre-season.
And at the bottom of the ranking, behind Force India, Lotus and Virgin, is McLaren, having done almost half of Ferrari's nearly 7000 kilometres.
"I'm not going to lie. It's not the best way to go into the season," admitted Jenson Button.
The MP4-26 was launched late after skipping the opening Valencia test, but it has since been plagued with exhaust, hydraulic and aerodynamic problems.
800 kilometres behind Ferrari on the mileage list is Red Bull, whose Christian Horner said the team has "never been so well prepared" for a new season.
Button insisted: "We are a long way down on it (mileage) but there is no point getting negative about it and down at this point of the season."
Third best was Sauber, ahead of Mercedes, Toro Rosso, Renault and Williams.