But that’s not an easy task, and frankly, what do you do if the previous model of your car debuted with the most powerful engine of its kind? Easy, you make it even more powerful for the new one.

The new M139 engine in the 2020 Mercedes-AMG A45 S is somewhat absurd: 310kW and 500Nm from a 2.0-litre engine that can meet the absolute latest in emissions regulations is a herculean task. One that makes a mockery of its competition with a 0–100km/h time of just 3.9 seconds. To put that into perspective, the all-new 992 Porsche 911 Carrera S does the same dash in 3.7 seconds. We are talking about the quintessential Porsche being just 200ms quicker than the cheapest ‘real’ AMG. These are the times.

In some ways, AMG has always been about outright power and brute force with the likes of the C63, E63 and the GT range, but the A45 plays a fine role in not only being powerful and fast in a straight line, but also having the ability to carve up a racetrack or a mountainous piece of road with relative ease. To find out if this was still the case, we flew all the way to Jarama Circuit in Spain to test what is perhaps the most anticipated AMG model since the original A45.

From the outside, the new A45 can be had with either an aero pack or in stealth. We kind of like both, but would say that without the big wing and the front aero trickery, the A45 can look a little underdone, but much more mature. Stick the rear wing and all the other goodies on, and all of a sudden you've got that boy-racer look we love and hate, so it really comes down to personal preference.

Either way, the A45 has a wider track and pumped guards compared to the regular A-Class. You really can’t miss the differences, be it the enormous quad 90mm exhausts in the rear sitting above a rather angry-looking diffuser, the unique side skirts, or those giant 360mm front brakes that copped endless abuse without a hint of fade.

The interior is a little more similar to what we are used to from its donor car, with the exception of a flat-bottom steering wheel that looks like it is taken straight out of an AMG GT R, sports seats with yellow accents, and the updated MBUX system that has AMG-specific displays for when Sport+ or Track mode is selected.

Other than that, though, the A45 is all about the drive. The car uses a newly developed and fully variable AWD 4MATIC+ system with torque control. To put it in simple terms, the new rear axle makes use of two electronically controlled multi-disc clutches, each connected to one rear axle driveshaft.

This allows the computers in the A45 to decide not only whether to send the might of the engine to the front or rear, but also which wheel on the rear end. Apart from allowing for better cornering, the ability to send most of the torque to the left or right rear wheels allows the enabling of drift mode. Watch a video of that on our Facebook page here.

Another performance upgrade for the A45 is the all-new eight-speed dual-clutch transmission, which believe it or not is taken from a B-Class diesel (with extensive modifications for this application). This allows for quicker gearshifts and also comes with the ability to handle significantly more torque than before.

Turn it on and the A45 is a little subdued. That’s an unfortunate consequence of European noise regulations, which have resulted in the new AMG having to pump the exhaust note into the cabin artificially in order to enhance the experience. Although we don’t share the same tough regulations in Australia, our cars will sound pretty much the same (apart from a slight difference in the exhaust frequency due to lack of a particulate filter).

It’s not that the new A45 sounds bad – not at all, it’s still a beast as it flies past – but it’s just not as loud or as theatrically expressive as the previous model, and the cracks and pops on lift-off are mostly gone. Thankfully, you simply drive it from your Mercedes-AMG dealer to a respectable exhaust shop and call the folks at Brabus and it will be sorted. We would go so far as to say if you’re going to pre-order an A45 (you really should), you may as well order the updated exhaust now.

In Comfort mode, the A45 is very much out of character. In the sense that, well, it’s actually comfortable. The previous A45 was jarring and the thought of having to drive one as a daily was not welcomed by anyone that valued their spine, but the new car is genuinely a good ride (our test cars had the adaptive suspension we believe will be standard fitment on Australian cars). We soaked up plenty of third-rate Spanish roads and the A45 dealt with the rough surfaces with relative ease.

Turn the dial to the right and there is a Sport mode, but really, if you’re going to leave Comfort mode, you may as well go to Sport+ or Track. The suspension immediately hardens up and the sound turns a little more aggressive, the gearshifts get more rapid, and the A45 we love and remember comes back to life with even more aggression.

Let's put it this way, the new A45 is stupendously fast. Not like a hot hatch fast, more… Just f#*king fast. To get a 0–100km/h time under four seconds in this car is really pushing the boundaries of what is possible. Besides, we had 40-degree temperatures in Spain, and even then it was evident we were dealing with a car that would laugh at supercars of old.

It’s interesting because from a driver’s perspective, the A45 actually doesn’t feel fast thanks to its insanely linear torque curve. There is no sudden rush of turbo boost, and the chassis is so damn tight that nothing moves or leans to give you that sensation of acceleration. It’s only when you peek down at the speedo and realise you’re doing three times the speed limit (not that we did, officer), that comprehension of the sheer acceleration takes place. It’s hard not to laugh when that happens... Not that we did. Promise.

Interestingly, our first test drive around the outskirts of Madrid in the A45 AMG led to some strange issues, with the steering being off with a lack of feel and response, and our particular test car being extremely prone to understeer into tight corners. This left us rather concerned given our expectations. We checked the tyres and nothing seemed amiss, but we swapped into two additional A45 test cars and these issues did not present themselves, so we are putting that to a specific car issue.

Once we had settled into a good review car, we found the best driving characteristic of the new A45 to be its willingness to oversteer at any given opportunity. The rear loves to step out (though not as much as the new CLA45) in a controlled fashion (select Sport for the ESC), and again this leaves you with a stupid grin that’s rather infectious for anyone else in the car that isn’t screaming for dear life.

The steering is super direct and the car is annoyingly good at maintaining its line. Once the Michelin Pilot Sport 4 S tyres heat up, you can certainly complain about a tad amount of understeer, but in good conditions it’s a solid dynamic package. AMG will offer the car with Cup 2 tyres at some point, but it would certainly be our second upgrade after the exhaust.

We had more than 30 laps around Jarama Circuit, and can safely report that while we couldn’t keep up with an ex-F1 driver in an AMG GT R, we would be confident in saying it could pretty much keep up with, if not overtake, anything in its price range. We can’t wait to put it up against the BMW M2 Competition, as the two cars are so different in how they drive, it would make an excellent comparison.

No matter how you want to look at it, the A45 is fast. It’s confidence-inspiring and it begs to be driven hard. It’s the ideal regular track car that looks just as at home in a Coles carpark as it does going flat out into a corner without even a thought of lifting. It’s a true AMG, and more than likely faster around most tight tracks than the likes of the current C63 AMG.

Mercedes-AMG claims 8.4L/100km on 98RON fuel, but don't expect to get anywhere near that with a heavy right foot.

Really, the only negatives are the lack of noise and the similar-to-A-Class interior. We don’t know yet how much it will cost, but hopefully you can take one home for about the $100K mark when it shows up in Australia in the first quarter of 2020. And for that price, you’re not going to find much that will outperform this.

It’s likely going to have a pretty big waitlist, so if you want one, you have our assurance that you won’t be disappointed.

Drive Rating

Overall – 8.9

Performance – 9.2

Ride Quality – 8.5

Handling & Dynamics – 9.0

Driver Technology – 9.2

Interior Comfort & Packaging – 8.7

Infotainment & Connectivity – 9.3

Fuel Efficiency – 7.8

Safety – 9.0

Value For Money – N/A

Fit For Purpose – 9.0