Vehicles from the 2012 model-year were the focus of the study, which is now into its 26th year, with 34,000 owners reporting problems they’ve experienced over the past 12 months after three years of ownership.
Over 170 specific problem symptoms are grouped into eight major categories, with the overall score determined by the number of problems per 100 vehicles.
Lexus’ score of 89 problems per 100 vehicles makes it the winner for 2015, while second-placed Buick averaged just over one problem per vehicle with a score of 110.
Toyota-owned Scion was one of the big improvers for 2015, lifting its rank 13 positions over the 2014 study, while Ram (score 134) and Mitsubishi (score 140) also showed improvement.
The industry-wide average was 147 problems per 100 vehicles.
Segment awards largely reflect the study results, with Toyota combined with its Lexus and Scion brands and General Motors’ combined Buick, Chevrolet and GMC brands each receiving seven awards.
Six of the top-ten problems were considered design-related, rather than defects or malfunctions, but around 30 percent of owners reported what they believed to be mechanical problems - mainly concerning rough shifting from automatic transmissions.
But the most common problems for owners related to voice recognition, Bluetooth and connectivity, with 55 percent saying their vehicle would not recognise their phone and 31 percent saying their phone would not automatically connect.
These results follow a call from J.D. Power’s Kristin Kolodge last year for carmakers to ‘start again’ with in-car voice recognition.
Around 15 percent of respondents said they would avoid a new model if it lacked certain technical features, compared to just four percent in 2014.