Created in the Affalterbach pleasure house of AMG, the new 2020 Mercedes-AMG CLA 45 and the 2020 Mercedes-AMG A45 have become the most potent automobiles powered by four-cylinder engines. With a "one man - one engine" philosophy, each Mercedes-AMG CLA 45 and A45 come with a hand-made “M139” 2.0-liter engine capable of delivering 382 horsepower or 416 horsepower (in its S version). Furthermore, both cars feature an eight-speed, dual-clutch automatic transmission and a clever 4Matic+ all-wheel-drive system.

As far as performance goes, I can tell you that the two cars that stormed up the Goodwood Hill yesterday can achieve 62 mph in 3.9 seconds (A 45 S), 4.0 seconds (CLA 45 S and A 45), and 4.1 seconds (CLA 45). Furthermore, if you pay for the AMG Driver’s Package, you can unlock the maximum speed of 168 mph (instead of a standard 155 mph).

The 2020 Mercedes-AMG A 45 and CLA 45 Have The Most Powerful Mass-production, 2.0-liter Engines

To put these cars and their power in perspective, let me tell you that the BMW M3 E92 and the first Audi R8 (an Audi halo car of the time) had V-8 engines with four (or so) liters of capacity that developed a tad less power compared to the four-cylinder units in the 2020 AMG CLA 45 and the 2020 AMG A 45. While this four-cylinder represents the ultimate in ICE design, I cannot but assume that AMG developed them to lower the average emissions across the lineup of the cars it manufactures.

Mercedes-AMG A45 drivetrain specifications

I can only remember one production car with a more powerful 2.0-liter four-cylinder engine - the Mitsubishi Lancer Evo X FQ-440 MR from 2014. It had a 2.0-liter, 440 horsepower, four-cylinder. The Japanese company only produced only 40 units to celebrate the 40th anniversary of Mitsubishi's operation in the U.K.

Remember, the A-class (a hatchback) and the CLA-class (a stylistically pleasing sedan) are, in essence, compact cars. The AMG versions grew on the pillars of their AMG 45 predecessors, but it seems that Mercedes-AMG took a step further to make these machines the most astonishing compact cars ever.

Mercedes-AMG CLA 45 drivetrain specifications

What's New For the 2020 Mercedes-AMG CLA 45 and the AMG A 45?

Starting from outside, the CLA 45 and the A 45 get vertical bars on the grill (just like other AMG products), deeper bumpers with larger air intakes that feed the radiators with air, and a full complement of aerodynamically enhancing features. Looking dangerous and brazen (especially with Selenite Grey Magno finish and an optional AMG Aerodynamics package with the AMG Night Package), the hatchback and the sedan seem to announce some insane performance and capabilities.

While the 2.0-liter four-cylinder, now with 416 horsepower and 369 pound-feet of torque provide all the fun, the hardware that translates all the power to the ground is quite something. It has two clutches on each axle that control every tiny bit of torque applied to the rear wheels. We have seen a similar technology on the larger Mercedes-AMG cars, and in this case, it enables the A 45 and the CLA 45 to have a so-called Drift mode. Two clutches in the back give you enough power to play with the rear end without killing yourself. When you are done with that sort of fun, the tech will help you lay down as much power to the ground as possible via 19-inch wheels. In essence, AMG can control the power delivered to the front and back wheels, as well as the power delivered to the right and left wheel. No other hatch has that ability right now.

Other curiosities include:

-* Independent rear suspension

-* Adjustable dampers (optional)

-* Massive 13.8-inch drilled brake discs up front

-* Far more structural enhancements for better rigidity compared to the standard CLA and the A-class

-* Roller bearings on the shafts of the compressor as in the high-end AMG GT four-door

-* New engine position (rotated by 180 degrees compared to the old one) that allows for better aerodynamic exterior design and straight exhaust manifolds

-* The aluminum plate under the engine - shearing plate - increases torsional rigidity

-* Diagonal struts at the front and rear of the underbody further improve rigidity

The Interior Of the Mercedes-AMG CLA 45 and AMG A 45

The changes are superficial (save for the seats), but they do add a bit of playfulness to the CLA and the A-class. I think you will be most impressed by the unique display readouts that present all the vital information, such as the oil temperature, engine temperature, transmission condition, lap and sector times, and all that. Go a bit madder with the money, and you can even get all the telemetry readouts such as the throttle position, g forces, and brake points. Telemetry is the part of the Track Pace option. Honestly, if you are to buy the car with the most powerful four-cylinder production engine ever, you better get this Track Pace option and drive your CLA 45 on the track.

Conclusion

Mercedes-AMG does not have any intentions to sell the A-class in the U.S. The same goes for the AMG A 35 and the AMG A 45. However, the AMG CLA 45 gained the same technology, the same engine, and the same options as the A 45, making it a far more flamboyant and presentable option in my mind. If you find the 416 horsepower-powerful CLA 45 S a bit too much, you can have a bit less powerful version with 387 horsepower. It is still more powerful compared to the old most powerful CLA 45 and more powerful compared to any other compact sedan on the market anywhere.

I don't have to remind you that despite all the machinery created to make the CLA 45 go as fast as possible, this can be a quite civilized car. Thanks to the AMG Dynamic selector, you can choose between four different modes (Basic, Advanced, Pro, and Master) to adjust the nature of the beast.

However, if you are not going to enjoy "Master" with the transmission set in "Sport", go buy the CLA 35. It will suit you better.

The Mercedes-AMG A 45 will not be available in the U.S., but you can expect the AMG CLA 45 to make a debut on our soil later this year. Better hurry up to Mercedes dealership and order one.

Further reading

Read our full review on the 2020 Mercedes-AMG A45.

Read our full review on the 2019 Mercedes-AMG A35.

Read our full review on the 2020 Mercedes-AMG CLA 35.

Read our in-depth review of the 2020 Mercedes-Benz CLA}

Read our full review on the next generation 2018 Mercedes-Benz A-Class.

Read our full review on the previous 2014 Mercedes-Benz A45 AMG.