First drive: 2019 Mercedes-AMG 53 series

We drive the mild-hybrid E53 Sedan, Coupe and Cabriolet, and CLS53 from Mercedes-Benz's AMG division.

Normally, a first-drive review would focus on a single model, but when Mercedes-Benz offered us the chance to come drive the new AMG 53 lineup in its entirety, we couldn't resist.

Since all of these models use the same fundamental drivetrain, we've decided to consolidate our impressions of the E53 lineup and CLS53 to a single review. Since we have a good deal of ground to cover, let's get started.

53 is the new 43

As is traditional with Mercedes-Benz, the "53" in each of these model names denotes a particular engine. In this case, it's a turbocharged, three-liter inline six featuring a 48-volt mild-hybrid system and an electric auxiliary compressor.

Neither a traditional supercharger (which would be belt-driven) nor a turbocharger (gas-driven), this compressor acts to smooth out mid-range power delivery, keeping the torque curve flat until the turbocharger builds boost.

Mercedes refers to the integrated starter-alternator and electric motor collectively as "EQ Boost," and it serves multiple purposes. In addition to keeping the almost-one-kilowatt-hour 48-volt battery topped off, it allows for a "glide mode," which sustains vehicle speed for brief periods without use of the gas engine.

It's also the mechanism by which stored power in the battery is used to increase performance off the line, and its output in this mode contributes 21 horsepower and a whopping 184 lb-ft of torque to the inline six's off-idle power reserve.

All of this works together to produce 429 total system horsepower and 384 lb-ft of torque. It's significantly more complex than the old biturbo V6 employed by the "43" series vehicles, but it actually packages a bit more efficiently thanks to the omission of belt-driven accessories (powered now by the hybrid system) and a cylinder bank.

If it seems like the Mercedes-AMG 43 series cars just debuted, that's because, in vehicle development terms, they pretty much did. The E43 sedan, which was sort of an oddball in the group anyway thanks to its more aggressive engine tuning, was quietly discontinued last year (though the engine is still available in the E450) to make room for the E53.

43 models are still available elsewhere in the lineup for the time being, but we expect them to be phased out as Mercedes migrates from the old V6 to this inline engine.

Power goes from this system to the ground by way of a nine-speed automatic transmission (no CVTs or planetary gearboxes for this hybrid) and standard 4Matic+ all-wheel-drive.

The lineup

The 53 treatment has so far been applied to the E-Class Sedan, E-Class Coupe, E-Class Cabriolet and CLS Coupe. We spent two days driving these four midsizers on the gorgeous back roads of Napa Valley and the Northern California coast so that we could get a handle on their unique characteristics.

E53 Sedan

We mentioned above that all four of these cars are essentially midsize sedans and coupes, so it should come as no surprise that they're packing a bit of heft. With a base curb weight of 4,341 pounds, the E53 Sedan was actually the lightest car we drove. This turned out to be a noteworthy distinction, as its comparatively slight frame didn't really shine through on the road. Even in this large-car pack, the E53 Sedan drove the biggest by far.

It wasn't that the Sedan felt less capable, exactly, but it seemed like a vehicle lacking a coherent mission. Comfort is supposed to be the E-Class's forte, and the AMG treatment will always be at odds with that. Unlike the balls-to-the-wall E63 model, where performance is the dominant philosophy, the E53 feels more like it was developed for two completely different customers simultaneously, with just enough taken from both approaches to complete the car, but not necessarily fully integrated.

That's not to say that the E53 Sedan is a bad car. In fact, it was the quietest and most comfortable of the bunch, and the only four-door we'd care to fill to its passenger capacity. At the same time, noise from the aggressive Pirelli run-flat summer tires and the large AMG-spec wheels constantly intruded into the otherwise serene cabin space. Those incongruities just couldn't be ignored.

We were surprised by our own conclusions, as the E-Class sedan was a highlight of the 43 lineup. This go-around, we'd probably just stick with the E450 (which carries on the old 43's spirit) and maybe throw in the AMG appearance package and Air Body Control to round it out.

E53 Coupe and Cabriolet

Now, these are equines of an entirely different hue. Though they're both heavier than the E53 Sedan (the Cabriolet was the heaviest in the group by 100 pounds), they felt immensely more dialed-in and aggressive. There was no confusion as to their missions. They're sporty cars and made no pretense of being otherwise.

This focus paid dividends on the road, encouraging us to push the two-doors harder than we did the Sedan. Even in sometimes-pouring rain, the E53 Coupe and Cabriolet bit hard out of the turns and encouraged us to explore every inch of available asphalt. AMG's tuning of the 4Matic+ all-wheel-drive system is excellent, and even with some deliberate ham-fistedness, we always got the best of the available grip.

Of the two, we'd pick the Coupe. The Cabriolet's structure is obviously reinforced more comprehensively, but even that extra bracing is no match for a metal roof. The same road surface imperfections that interrupted our enjoyment of the Sedan were amplified in these firmer-riding two-door model and further magnified by the soft top, which offered up some shimmies and rattles that were absent in the Coupe. It's the sort of intrusion that vanishes when you get to enjoy a top-down drive, but thanks to the weather, we had no chcoice but to deal with them with the roof in place.

CLS53 Coupe

Yes, it's a four-door. We're over it by now; you probably should be too.

If you must have a 53 model with four doors, this is the one you want. The CLS combines the sharper tuning of the E53 Coupe with most of the practicality you get from the Sedan. The CLS's style-forward lines reflect its more youthful mission, which allowed AMG's engineers to go a little more wild than mild--the opposite of their approach with the Sedan.

That the CLS53 has more personality than the E53 Sedan should then come as no surprise. In fact, its rougher edge occasionally bordered on the un-Mercedes-like, but in a charming way, rather than an obtrusive one. Unlike the Sedan, the CLS manages to shrink around the driver and impart a sensation of speed appropriate to the moment.

All or nothing

No matter which of these cars we happened to be driving, a few things stood out. We mentioned the tire and suspension noise before, but it bears reiterating. These aren't isolated executive cars; they're sport coupes and sedans. Thankfully, another consistent high note amongst all of them was their steering, which offered respectable feedback and glance-away confidence free of the constant need for corrections. Just don't look away long enough to miss spotting a pothole. Your kidneys will thank you.

Overall, we came away impressed by Mercedes-Benz's new AMG drivetrain. It is the epitome of linearity and predictable delivery. It can sometimes feel a bit too clinical, but that's a common critique of Germany's turbocharged engines. Character exists in imperfections, and those are glaringly absent in applications such as these.

Having the opportunity to drive all four of these models back-to-back made it clear that Mercedes-Benz's product development teams put a great deal of thought into differentiating them, which makes it easier for us to appreciate that each one has a role. We have our preferences, but by and large, these are decent performance cars with myriad creature comforts just a ticked-box away. While some will dismiss these new models as further dilution of the performance division's formula, we've come to accept the aggressive segmentation now prevalent throughout the luxury space.

Leftlane's bottom line

The 53 powertrain is proof that mild-hybrid performance cars are ready for prime time. The flexibility and raw performance of this new system more than make up for its weight penalty and rather than detracting from the drive experience, actually manage to enhance it. We'd skip the Sedan (Give us the E63 S, thanks.) but either Coupe would make a dandy addition to any driveway within a quick drive of some decent roads.

2019 Mercedes-AMG E53 Sedan base price, $72,550; 2019 Mercedes-AMG E53 Coupe base price, $73,700; 2019 Mercedes-AMG E53 Cabriolet base price, $80,350; 2019 Mercedes-AMG CLS53 Coupe base price, $79,900; Destination, $995

Photos courtesy of Mercedes-Benz