Cars are 6 percent less reliable than they were last year, an annual survey by J.D. Power shows, with American car owners reporting an increase in problems with their vehicles for the first time in 15 years.
The survey is based on responses collected from 41,000 owners of 2011 model-year vehicles, and determines different models' dependability after three years of ownership. Researchers found that the overall number of reported issues increased from 126 problems per 100 vehicles in 2013 to 133 problems per 100 vehicles this year.
The last time vehicle reliability worsened was 1998.
"Until this year, we have seen a continual improvement in vehicle dependability," said David Sargent, vice president of global automotive at J.D. Power. "However, some of the changes that automakers implemented for the 2011 model year have led to a noticeable increase in problems reported."
The rise in reliability issues may be a result of automakers' recent rush to improve fuel economy, Sargent said, which has sometimes led to engine hesitation, rough transmission shifts and lack of power.
A study by the University of Michigan showed last year that average fuel-economy ratings have improved from 20.5 miles per gallon in January 2008 to 24.9 mpg in January 2014, as the White House has driven a campaign to raise fuel economy standards to 54.5 mpg by 2025.
Lexus topped J.D. Power's reliability list for the third year in a row with 68 problems reported for every 100 vehicles, followed by Mercedes-Benz and Cadillac.