Calculated from data collected from approximately eight million technical inspections between June 2010 and June 2011, the agency found that the Porsche 911 has been the car with the fewest reported defects of vehicles built since 2000. This is regardless of the kilometres travelled by the vehicles.
Before any vehicle model is added into the rankings, it has to have been inspected at least 500 times. TÜV has found that in the 10- to 11-year-old category for the 2011 report, the Porsche 911 had the least faults with a fault rate of 8.3 per cent, followed by the Toyota RAV4 (10.5 per cent), and then the Porsche Boxster (11.2 per cent).
In the eight- to nine-year-old vehicle category, it's the Porsche 911 out in front again, with a fault rate of 8.3 per cent, followed by the Porsche Boxster (9.8 per cent), and the Toyota RAV4 (10.2 per cent).
In the six- to seven-year-old vehicle category, again, it's the Porsche 911, with a fault rate of 5.5 per cent, followed by the Porsche Boxster (7.1 per cent), and the Subaru Forester (7.3 per cent).
In the four- to five-year-old vehicle category, it's a three-way tie for first, with the Porsche Boxster, Porsche Cayman and Toyota Corolla Verso all reporting a fault rate of 4.2 per cent, followed by the Porsche 911 (4.6 per cent), and Porsche Cayenne (5.0 per cent).
Lastly, in the two- to three-year-old vehicle category, the Toyota Prius is recorded as having the least faults, with a fault rate of 2.2 per cent, with the Mazda2, Toyota Auris (Corolla) and Porsche 911 all as the equal-second-least defective vehicles (2.3 per cent), and then the Smart Fortwo (2.5 per cent).