Mercedes-AMG just dropped three new high-performance models — and dropped an all-new inline-six engine in each. The allure of an inline-six (or straight-six) — in which cylinders are literally in a straight line, rather than a “V” formation à la V6 engines — is that they are well-balanced, keeping power delivery silky smooth. Notably, Jeep utilized (note: past tense) the engine configuration in its Cherokee and Wrangler models for years, and BMW still relies on the performance attributes of the single-file arrangement. The inline engine is costlier to produce than V-configurated engine blocks, hence its low take-rate. But Mercedes-AMG has pulled the wraps off its newest car lineup, the inline-six-powered 53 range, which replaces the V6-powered “43” vehicles.
The CLS53, E53 and E53 Cabriolet are the first models to launch with the new power plant, which is good for 429 horsepower (up from 396 in the 43 models) and 384 lb-ft of torque. What’s more exciting about the inline-six itself is how it makes its power. Replacing the alternator and starter is an electric motor that Mercedes-AMG is calling EQ Boost. It produces 21 horses and 184 of the lb-ft; plus, turbo lag is mitigated with an electric compressor. What that translates to is more power when you want it and better efficiency overall, especially when paired with the brand’s nine-speed automatic and 4MATIC+ all-wheel-drive. Bottom line: 4.4 seconds to 60 in the new CLS53, which is fine by us, no matter how it happens.