The 53 line is powered by a new electrified 3.0-liter inline six-cylinder engine and will include variants of the redesigned CLS, E-class coupe and E-class convertible. The new engine, which has a 48-volt electrical system, generates 429 hp and 384 pound feet of torque. A starter-alternator can momentarily boost output by an additional 21 hp, plus 184 pound feet of torque. Parent Daimler AG introduced the new 48-volt engine last year in some S-class models designated for other markets. The CLS53, E53 coupe and E53 convertible are the first applications of the engine for the U.S.