14. Acura Vigor
The Acura Vigor, produced from 1992 to 1994, was a mid-size sedan that uniquely featured a 2.5-liter inline-five engine, delivering 176 horsepower. (motortrend.com) Positioned between the Integra and Legend in Acura’s lineup, it offered a distinctive alternative to the more common four- and six-cylinder options. Despite its performance and unique engine configuration, the Vigor struggled with sales and was discontinued after just three years, replaced by the Acura TL. (carscoops.com)