For the first time since 1998, J.D. Power and Associates' annual Vehicle Dependability Study has showed a decline in average dependability, compared to the year before.
The study assesses the dependability of three-year-old vehicles, so the 2014 survey dealt with 2011 models.
It showed that, on average, their dependability was 6% lower than for the 2010 vehicles in the previous year's survey – based on problems reported per 100 vehicles (PPT).
The average score in the 2014 study was 133 PPT, compared to 126 in 2013.
The study was based on interviews with more than 41,000 owners of 2011 model-year cars and trucks in the United States.
Most of the increased problems reported fell under the categories of engine and transmissions, a trend Power attributes to the ongoing quest for improved fuel economy.
To that end, manufacturers have increasingly moved toward smaller engines with higher specific power output (hp/litre), as well as to more complex transmissions.
The study notes that the decline in dependability numbers is particularly pronounced for four-cylinder engines, particularly those with turbochargers.
Another common source of problems is hands-free communication and navigation systems that, although increasingly popular, tend to be trouble prone.
In spite of the upturn in overall problems, there was little change in the 2014 dependability study's overall ranking of brands.