Filed under: Car Buying , Lexus , Porsche , Toyota Each year, J.D. Power and Associates surveys original owners of three-year-old vehicles to find out what kinds of problems they have had experienced over the last 12 months, and then it uses this data to create its annual Vehicle Dependability Study . This means that the models in the 2013 study are 2010 model year vehicles, and J.D. Power rates each make as well as the top individual models based on how many problems were experienced per 100 vehicles (PP100). Debunking the idea that carryover models are more dependable than new or updated models, the 2013 study found that the average carryover model experienced 133 PP100, while all-new or redesigned vehicles for the 2010 model year had 116 PP100; vehicles that received minor changes fared the best with just 111 PP100. The overall average for all makes was 126 PP100, which is the lowest figure since the findings were first issued in 1989. For 2013, Lexus and Porsche remained in the top two spots, respectively (and each experienced fewer problems year over year), but there were plenty of shakeups elsewhere in the list. The biggest mover overall was Ram , which moved up 20 spots from one of the worst performers in 2012 to sitting pretty in the top 10. Other big positive movers include Mazda , Infiniti and Ford . On the opposite side of things, Scion dropped 13 spots, falling from the fifth-best score down to No.