DETROIT -- Mercedes-AMG's new midrange 53 line -- with three models going on sale in the U.S. late this year -- is the latest step in the luxury brand's strategy to converge performance and electrification.

The 53 models are 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 AMG 53 models for the 2019 model year were set to debut Monday during the Detroit auto show.

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.

"With the new 53-series models, we are extending our portfolio in a first step towards a hybridized future," Mercedes-AMG Chairman Tobias Moers said in a statement.

The engine will enhance the performance and driving dynamics associated with AMG while at the same time reducing fuel consumption and emissions, Mercedes said. The CLS53 accelerates from zero to 60 mph in 4.4 seconds.

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.

Distinguishing design features shared among the new 53 models include a twin-blade radiator grille in silver chrome, an A-wing front bumper design, AMG-specific side sill panels, a rear bumper with diffuser insert and round exhaust tailpipe trim in high-gloss chrome.

With the new 53 line, the CLS will no longer have a top-of-the-line AMG 63 model, Moers has said.