Sunny Spain, with its winding roads up the serrated Montserrat mountains surrounding Barcelona, was a perfect place to gauge the latest Mercedes-Benz CLS. It’s a chance to sample the four-door coupe’s performance and handling, appreciate the exhaust notes from the new inline-six, and welcome an expanded lineup that now includes the first Mercedes-AMG CLS 53. A short rain shower seemed cued up to showcase the all-wheel-drive system, as well.
It was an opportunity to see if the third-generation CLS can hold court in the segment it created when it showed the first concept at the Frankfurt auto show back in 2003. Despite the apparent contradiction of the idea of a “four-door coupe,” since then, the world has become enamored with the idea of coupelike lines overlaid on sedan structure. The body style has resonated with 375,000 CLS buyers around the world and has spurred competitors to create their own four-door fastbacks. Mercedes even trumped itself at this year’s Geneva auto show, where it unveiled the even sexier Mercedes-AMG GT four-door coupe.
But the German carmaker has not forgotten that the CLS started it all. For the 2019 model year, the CLS family gets a new and cleaner design, new engine portfolio, and hybridization with a new 48-volt system that the automaker sees as a crucial next step in an automotive world that is becoming increasingly electrified.
At launch there are new 3.0-liter inline-six engines: a gasoline and a diesel. The U.S. only gets the gasoline version, which generates 362 hp and 369 lb-ft of torque in the CLS 450 but which also has the EQ Boost mild-hybrid system and 48-volt electrical system.
After launch, Mercedes is adding a 2.0-liter four-cylinder gas engine with a belt-driven starter alternator and 48-volt system—but it is not for the U.S., either. There are no specs yet, but officials say it will produce more than 300 hp.
The CLS 53 ups the performance to 429 hp and 384 lb-ft out of the I-6 by adding a twin-scroll turbocharger and an electric auxiliary compressor that builds boost until the turbocharger kicks in. Voila, no turbo lag. Acceleration is not neck-snapping but it is quick for a two-ton sedan: Mercedes claims it will do 0–60 mph in 4.5 seconds. Smooth, too.
For the CLS 450, Mercedes combines the starter and a generator in an electric motor positioned between the engine and transmission. The extra 22 hp and 184 lb-ft helps ensure power is at the ready and eliminates any lag before the twin-scroll turbocharger kicks in. The electric supercharger in the CLS 53 makes it even quicker off the mark, but again the power delivery is very linear. The other advantage is a seamless start/stop—we never felt the engine turn on or off—and the ability to “sail” when the engine disconnects from the transmission and coasts.