Mercedes-AMG adds new -53 lineup with 429-hp I6
The straight six is back, and it makes the -43's V6 look like a chump.

If you want to buy into the Mercedes-AMG lineup without spending six figures on an obscenely powerful car, the mid-tier -43 range is for you. Or, rather, it was, because there's a new sheriff in town.
Mercedes-Benz announced at the 2018 Detroit Auto Show that it will introduce a new line of -53 models. The first three it's showing off are the Mercedes-AMG CLS53, E53 Coupe and E53 Cabriolet. In addition to packing a new engine, this new AMG line also includes a touch of hybrid goodness.
At the heart of the change is a new inline-6 engine, replacing the -43's V6. Its output is a meaty 429 horsepower and 384 pound-feet of torque. All three models with this new engine come with a nine-speed automatic and all-wheel drive. This is a huge bump compared to the 396 hp from the -43 lineup's six-cylinder.
Instead of using a traditional starter and alternator, Mercedes-AMG replaced both items with a single electric motor, which it calls EQ Boost. Part of a 48-volt mild hybrid system, EQ Boost can provide an extra 21 horsepower and 184 pound-feet of torque to the wheels. It also provides for stop-start functionality and a "gliding" mode that disconnects the engine from the transmission when coasting. An electric compressor can help build turbo boost, too, providing for minimal turbo lag during spirited driving.
As with other Mercedes-AMG models, there are some special bits separating the -53s from the rest. All -53 models share a chrome, twin-blade radiator grille and a front splitter in the same color. AMG prides itself on tailpipe design, and the -53 models rock a set of four round tailpipes in direct contrast to the -63 lineup's trapezoidal units.
Additional parts included on AMG's new -53 models include an AMG Performance steering wheel, a three-mode air suspension system and big, 14.6-inch front brakes (the rears are nearly as big, measuring 14.2 inches). While the cars won't carry semi-autonomous driving features unless specifically optioned, standard equipment includes automatic emergency braking.
Mercedes-Benz has not yet mentioned pricing for the three initial AMG -53 models, but all three should be on sale in the US by year's end.