The 2020 Mercedes-AMG A45 is the range-topping version of the fourth-generation A-Class hatchback. Unveiled in 2019, it slots above the AMG A35 in the range thanks to a more powerful engine, a more aggressive exterior, and extra equipment on the inside. Powered by a redesigned version of the AMG-tuned four-cylinder engine that cranks out 382 horsepower, the 2020 AMG A45 is the most powerful A-Class to date. But for the first time ever, Mercedes-Benz introduced an S-badged version of the hatchback, with even more power. In this tune, the AMG A45 delivers an amazing 416 horses, more than any other hot-hatch on the market as of 2020. This four-cylinder is also the most powerful of its kind in production, as well as the engine with the highest horsepower per liter. Let's find out more about the 2020 Mercedes-AMG A45 in the comprehensive review below.

Exterior

Having already seen the regular A-Class and the A35, the A45 looks awfully familiar. But there are a few important changes to talk about, starting with the grille. This makes the A45 the first compact AMG to feature this grille. The front bumper also seems borrowed from the bigger AMG models. It features larger side vents with horizontal slats and a revised wing layout into the center intake. The side winglets seen on the A35 model are present here as well.

The engine hood remains similar to the standard model, which is a bit disappointing, but Mercedes says it's for aerodynamic purposes. Another feature that set's the A45 apart from other A-Class models is the wider design of the front fenders, as well as he flared wheel arches. Both accommodate a wider front axle.

Front the sides, the A45 is almost identical to the less powerful A35. The beefed-up hatchback rides a tad lower, and the side skirts are a bit taller, but it's difficult to tell the difference. The spoiler on the tailgate also looks similar, so it doesn't help the A45 stand.

But the wheels do, as the hatchback rides on 18-inch rollers in a 10-spoke design and finished in Tantalum Grey in standard trim. Go with the AMG A45 S model, and you'll get larger, 19-inch rollers. These feature a five-spoke design and are also painted in Tantalum Grey, but with a high-sheen finish. Finally, Mercedes offers an optional set of 19-inch forged wheels with a cross-spoke design and finished either in Titanium Grey with high-sheen or Matt Black with high-sheen flage and simulated central lock in aluminum.

Around back, the A45 is again identical to its less powerful siblings, save for the lower bumper. The spoiler atop the tailgate is similar to the A35's, but it's finished in body color as standard. On the A35, the spoiler is black, no matter the body color. The diffuser is also borrowed from the AMG A35, as it features the same vertical two fins in the center. However, the A45 features a twin tailpipe design, whereas the A35 has just one on each side. The outlets are also larger at 3.2 inches. Opt for the A45 S model, and the tailpipes grow even bigger at 3.5 inches and feature internal fluting and "AMG" lettering.

If you're a big fan of blacked-out body elements, Mercedes-Benz offers the familiar AMG Night package for the AMG A45. The bundle adds high-gloss paint to the front splitter, inserts in the bumpers and side skirts, and black chrome exhaust pipes.

Interior

Just like the exterior, the interior is a slightly beefed-up version of the AMG A35. The materials are also of a slightly higher quality in the standard layout. It includes the same wing-shaped, multi-tier dashboard, high-tech-looking center stack, and the turbine air vents. It also features the company’s latest 10.25-inch displays placed next to each other, which makes it seem like the car has one large screen stretching from behind the steering wheel to the passenger-side dash.

Just like the AMG A35, the AMG A45 stands out thanks to several unique features. The standard upholstery, for instance, combines black Artico leather and Dinamica microfiber with double stitching in red. The optional upholstery is special too, as it comes in Neva Grey and Black, grey stitching, and aluminum trim. No carbon-fiber, unfortunately. The A45 is also fitted with red seatbelts and chrome A/C vents with red rings. The A45 S stands ou a bit more thanks to yellow highlights inspired from racing. Specifically, it features yellow stitching, a yellow 12 o'clock stripe on the steering wheel, and yellow AMG buttons and ambient lighting.

The steering wheel features a flat bottom and is very similar to the A35, but it comes with extras like perforated leather on the grip area and contrast stitching. It includes built-in touch control buttons that can be used to intuitively select the displays of the instrument cluster and the multimedia system by means of horizontal and vertical swiping, just like on a smartphone.

These new seats provide increased lateral support not only for spirited driving on the highway but also for track performance. You also get brushed stainless steel sports pedals with rubber studs, black floor mats with "AMG" lettering, and a surround in a Nubuck leather look.

The two displays also sport bespoke start-up screens and apps. The instrument cluster can be customized in three ways: Classic, Sport, and Supersport. The later features a central, round rev counter and additional information in the form of bars to the left and right. Using the AMG menu, you can activate various special displays. There's Gear display with a yellow "M" symbol in manual mode and Warm-Up menu, which includes engine and transmission oil temperature. The Set-Up menu activates the AMG DYNAMIC SELECT settings, while G-Meter shows longitudinal and lateral acceleration forces. The familiar Race-Timer features activates the stopwatch, lap and sector times, while Engine data displays output and torque, engine oil and transmission oil temperature.

Of course, the AMG A45 also comes with the company’s latest MBUX infotainment system. It has the ability to learn thanks to artificial intelligence, it’s highly customizable, and includes all the latest apps and connectivity features. The A45 also features the AMG Track Pace, a virtual race engineer that keeps you posted on-track performance. It records more than 80 performance-related data and displays lap and sector times if you’re using it on the track, and it keeps track of reference times so you can improve your benchmarks.

AMG Track Pace also uses GPS and other sensors to detect when you leave a race track or shorten your lap. The app already includes maps for tracks like the Nurburgring or Spa Francorchamps, but you can record your own circuits.

The hatchback now offers 13 cubic feet of cargo room, a minor one-pound-foot increase compared to the outgoing model. That’s 1.1 cubic feet more than the Audi RS3 Sportback, the A45’s closest rival, which is rated at 11.8 cubic feet. BMW doesn’t offer a full-fledged M version of the 1 Series, but we can compare it to the M135i. The Bimmer offers a bit more room at 13.4 cubic feet.

With the rear seats folded flat, the AMG A45 swallows up to 42.7 cubic feet of luggage. That’s 1.2 cubic feet more than the Audi RS3 Sportback and a minor 0.3 cubic feet more than the BMW M135i. These rival hatchbacks are rated at 41.5 and 42.4 cubic feet, respectively.

Compared to its sedan counterpart, the A-Class Sedan, which will also spawn an AMG A45 version soon, the hatchback offers less luggage room behind the second-row seats. The sedan is rated at 14.8 cubic feet, which accounts for an extra 1.8 cubic feet. It’s not much, but it could make a difference. Obviously, the hatchback wins by a large margin when the second-row seats are folded.

Drivetrain

Called the M139, it's a heavily revised version of the old M133 with a higher compression ratio and a turbocharged placed behind the engine for better airflow management.

The placement of the engine is also completely new. While the old A45 and current A35 feature a transverse layout, the new engine is positioned longitudinally. This means that the turbocharger and the exhaust manifold are now placed in the rear and the intake system at the front. This design allows the flattest, most aerodynamic front section layout possible. and It also allows improved air ducting with shorter distances for both the intake and the exhaust.

As far as output goes, the mill cranks out 382 horsepower and 354 pound-feet of torque. That's an extra six horses and an additional four pound-feet of torque compared to the old A45. Not much of an update, right? But wait, because there's more. For the first time ever, the AMG A45 is available with an S upgrade that generates more oomph.

The new AMG A45 S places Mercedes-Benz at the top of the segment in terms of performance. While the old A45 wasn't powerful enough for the Audi RS3, which features a 2.5-liter five-cylinder mill rated at 400 horsepower and 354 pound-feet, the new A45 S delivers an extra 16 horsepower and similar torque. Granted, 16 horses isn't much, but it's enough to crown the A45 S as the most powerful premium hatchback on the market. Also, the AMG A45 generates a bit more oomph than the BMW M2 Competition, which cranks out 404 horsepower thanks to a 3.0-liter inline-six engine. Of course, the M2 isn’t a proper competitor for the AMG A45, but the upcoming 1M, based on the latest 1 Series, will probably have a similar engine and output.

So how quick is the new A45? The standard model hits 62 mph in exactly four seconds, which is two tenths quicker than the old hatchback. The A45 S reaches the same benchmark in 3.9 clicks, or three ticks faster than the outgoing model.

Versus the competition, the AMG A45 is the quickest option. While the old hatch was a tenth-second slower than the Audi RS3, rated at 4.1 seconds, the redesigned A45 is a tenth-second quicker in standard trim and two tenths faster in S spec. The same is available when compared to the BMW M2 Competition. The quickest 1 Series model, the M135i xDrive, is 0.8 seconds slower than the AMG A45 S.

As far as top speed goes, the new AMG A45 is locked at the usual 155 mph. The AMG A45 S tops out higher at 168 mph. That's a bit lower than the RS3, which can have a top speed of 174 mph with an optional package. The base A45 will also hit 168 mph if you get the AMG Driver's Package.

The transmission is also new. Mercedes-Benz replaced the previous seven-speed dual-clutch with the new eight-speed unit. Featuring new gear ratios for quick acceleration in all speed ranges, it also delivers fast shifting, no matter the gear. The standard Race-Start function allows maximum acceleration from a standing start and is responsible for the quick 0-to-62 charge times.

The AMG A45 is operable through six driving modes. Each changes characteristics for the throttle, shift times and timing, transmissions, AMG Dynamics, the exhaust system, and the chassis. Modes include Slippery, Comfort, Sport, Sport+, and Race.

Slippery was obviously design to improve stability on slippery and icy road surfaces. It features a flat torque curve, smooth gear changes, and earlier up shifts. Comfort is mostly for fuel efficient driving, mostly daily driving and when you don't want to floor the gas pedal. It uses early up shifts, comfort settings for the suspension, and an active start/stop function.

Sport mode enables a more agile response to gas pedal input, shorter shift times, and a more dynamic setup for he suspension and steering. Sport+ takes all of the above up a notch with an even more agile throttle response, an even more dynamic setup for the suspension and steering, and increase idle speed for faster acceleration. Finally, Race mode is dedicated to track racing and changes all parameters for maximum performance.

Chassis, Suspension, and Brakes

This department makes a big difference compared to the standard A-Class and even the AMG A35. Unlike its siblings, the A45 features a lightweight aluminium plate bolted underneath the engine for increased torsional rigidity in the front. It also features a strut tower brace between the front suspension struts and pistol-shaped "shotguns" connecting the side members to the A-pillars to minimize movements of the front section.

Diagonal struts at the front and rear of the underbody further improve rigidity. Mercedes says that all of the above make the suspension system respond more precise and will give you clearly defined feedback and less rolling and pitching on bends, when braking and during load cycles.

The suspension itself is a new design from AMG with bespoke spring elements and frequency-selective shock absorbers. Although it's more comfortable than the previous model, it also acts better at high speed as it can handle a higher maximum lateral acceleration with easier vehicle control at the limit.

The front end features a McPherson strut design with one wishbone below the wheel center, one sprint strut, and one tie rod. The new wishbone, made from aluminum, reduces the unsprung masses enabling a more sensitive response from the springs, while the front axle carrier is rigidly attached and stiffens the front section even more. The four-link rear suspension is also rigidly connected to the body via a rear axle carrier. It also includes three transverse control arms and one trailing arm plus specific bearings at each rear wheel. This design, based on those used in race cars, ensures maximum driving stability and agility.

If you want to take things up a notch you can order the optional AMG Ride Control, an adaptive damping system with three different control modes. Like most adjustable systems in the car, it ranges from comfort-focused to sporty. The system operates automatically by adapting the damping forces for each wheel according to the driving situation and road conditions. The system needs only milliseconds to adjust and is infinitely variable, with a wide spread of damping characteristics.

Stopping power comes from a high-performance braking system with fade-resistant components. The base AMG A45 features four-piston front calipers on 13.8-inch discs in the front and one-piston calipers on 13-inch discs in the rear. The discs are ventilated and perforated. The AMG A45 S model can be fitted with the AMG Dynamic Plus package that adds six-piston calipers and 14.2-inch discs in the front.

Safety

The hatchback is equipped with an impressive array of active and passive systems, starting with the car’s ability to keep a close eye on the traffic with an improved camera and radar systems that allow it to see up to 500 meters (0.3 miles) ahead. The use of navigation data and the Active Distance Assist Distronic system give the sedan semi-autonomous capability, a unique feature in this class.

The AMG A45 includes features like Active Emergency Stop Assist, Active Lane Change Assist, and Active Brake Assist as standard. The Pre-Safe Plus, borrowed from larger models, is available as an option. Passive features include airbags for the driver and front passenger, a driver’s knee bag, and window airbags on both sides as standard. The latter also covers the A-pillar, yet another benchmark for this segment. Thorax-pelvis side bags are standard in the front and optional for the rear passenger compartment.

Prices

The A-Class is not available in the United States and the AMG models won't come here either. The hot-hatch is available in Europe though. In the United Kingdom, the AMG A45 comes in at £48,495. That's a whopping £11,800 more than the A35 and more than twice more expensive than the base A-Class, which retails from £22,745. The AMG A45 S charges even more at £54,495, so the extra power and features will set you back an extra £6,000 compared to the A45.

Compared to its main rival, the Audi RS3 Sportback, the AMG A45 is only slightly more expensive. The RS3 comes in at £46,285, but you must bear in mind that this hot-hatch is based on a fairly old platform and design. The most expensive version of the BMW 1 Series, the M135i, starts from £36,430, but it's nowhere near as powerful and fast as the AMG A45. Should BMW offer a proper M version of the hatchback, it will probably cost at least £48,000 and match the Merc's sticker. For reference, the BMW M2 Competition comes in at £51,150.

Competition

Audi RS3 Sportback

The RS3 may be only five years old as of 2020, but it’s actually a bit long in the tooth since it’s based on a hatchback that went into production back in 2012. The good news is that Audi updated the model 2017, so it has a few fresh design cues to brag about. Granted, its interior doesn’t look as cool, and the technology isn’t as good, but the RS3 Sportback has enough power to stand up to the AMG A45. Its 2.5-liter five-cylinder engine, a rarity among the four-cylinder units that power most hatchbacks, cranks out a solid 400 horsepower and 354 pound-feet of torque. The sprint to 62 mph takes only 4.1, while top speed goes up to 174 mph with the Dynamic Package. Sure, the RS3 Sportback is no match for the range-topping AMG A45 S, but a redesign is expected soon, and this means that a new-generation RS3 with more power could arrive in 2020. Meanwhile, the old RS3 Sportback retails from £46,285. Just like the AMG A45, the RS3 isn’t available in the United States in hatchback form.

Read our full story on the 2020 Audi RS3 Sportback

BMW 1M

The BMW 1M doesn’t exist just yet, but the nameplate might return with the new-generation 1 Series. The brand-new hatchback was unveiled in May 2019 and marks a radical shift from a rear-wheel- to a front-wheel-drive architecture. Until the 1M makes a comeback though, you’re stuck with the old-generation M135i. As the name suggests, this isn’t a full-fledged M car, but a model that’s better suited to tackle the AMG A35 model. Powered by a 3.0-liter six-cylinder, the M135i comes with "only" 302 horsepower and 332 pound-feet of torque on tap. It’s obviously slower than the AMG A45, as it needs 4.8 seconds to hit 62 mph from a standing start. Top speed is limited to 155 mph, with no option to increase it to 174 mph. The 1 Series isn’t offered in the United States. U.K. pricing for the five-door model starts from £36,430.

Read our speculative review of the BMW 1M

Conclusion

The previous-generation Mercedes-AMG A45 set a new standard on the premium performance hatchback market and needless to say, the new model takes things to a whole new level in just about every department. With the existing Audi RS3 Sportback barely able to keep up with the outgoing Merc and BMW not yet offering a proper M version of the 1 Series, Mercedes-Benz will once again dominate this segment. At least of a few more years, until the competition comes up with proper rivals. The sad news is that this hatchback isn't coming to the U.S., so you'll have to settle for the sedan version of the AMG A45, set to debut sometime in 2020. It will be just as cool and fast, but it won't have the enhanced trunk of a hatchback with the rear seats folded flat.