Forget about Toyota or Volkswagen (pre-Dieselgate): Mazda is the most fuel-efficient car manufacturer in the U.S. according to the Environmental Protection Agency’s (EPA) most recent Light Duty Fuel Economy Trends report.

It’s the fourth consecutive year that Mazda has achieved the highest fuel efficiency of any mainstream automaker, and this without offering a single hybrid or electric vehicle.

For the 2015 model year, the small Japanese company led the way with a fleet-wide adjusted fuel economy performance of 29.6 miles per gallon (MPG). Obviously, much of the credit goes to Mazda’s unique SKYACTIV technology, which consists in component and engineering technologies intended to cut vehicle weight, improve engine efficiency, and bolster vehicle dynamics for outstanding environmental and safety performance.

All Mazda vehicles now feature SKYACTIV powertrains, from the little MX-5 roadster to the full-size CX-9 crossover.

Four manufacturers were closely grouped behind Mazda—Honda, Nissan, Subaru, and Hyundai in that order—with adjusted fuel economy values between 28.9 and 27.8 mpg, according to the EPA. Fiat-Chrysler had the lowest adjusted fuel economy of 21.8 mpg, followed by General Motors and Ford. Honda achieved the largest increase in adjusted fuel economy from MY 2014-2015, followed by Nissan.