Direct-injection engines were introduced with a promise that sounded ideal: more power, better fuel efficiency, and cleaner emissions, all from a more precise way of delivering fuel. On paper, the ...

While Hyundai and Kia have been rolling out impressive new EVs like the Ioniq 5 N and Kia EV9 and redesigning existing models like the Sonata, the automaker still has the lingering problem of bad ...