Porsche ranked highest among luxury brands in the J.D. Power 2019 U.S. Sales Satisfaction Index Study released on Wednesday.
Buick ranked highest among mass-market brands for the third time in four years.
Porsche earned 827 points on the index, down one point from an 828-point top rank last year. This was the second straight year for Porsche to top the rankings and the fourth time since 2015.
Klaus Zellmer, CEO of Porsche Cars North America, said in a statement that this was the first time the brand finished atop two of J.D. Power's key indexes in the same year -- the SSI and Customer Satisfaction.
Mercedes-Benz finished a close second with 825 points, a 10-point increase from 2018. Infiniti came in third at 821 points, down three points from its second-place rank last year.
Alfa Romeo had the best improvement among the brands, year over year, with an increase of 39 points from 2018.
Overall, the luxury-brand average stayed the same from 2018 to 2019 at 805 points.
The Porsche, Infiniti, Audi, Land Rover and Genesis brands all saw their scores decline.