Test-driving the new Mercedes-Benz inline-six engine | Straight but not narrow

Mercedes-Benz was once enamored of the straight-six gasoline-powered engine. It was a stalwart in the brand’s lineup, from the 3.9-liter supercharged M836 motor that powered its luxurious and sporty sedans in the mid-1920s until the 3.0-liter DOHC unit used in the W202 C-Class at the tail end of the 20th century.