While early news that the A 45 would deliver upwards of 245kW and 400Nm was no lie, it fell a little short of the car's actual figures.
Here's the truth of it: driven by a stove-hot turbocharged four-cylinder engine, the newest AMG model is packing a monumental 265kW and 450Nm of torque.
Sent to the 4Matic all-wheel-drive system through AMG's seven-speed SpeedShift dual-clutch transmission, Mercedes says that all that mumbo will shove the A 45 to 100km/h in just 4.6 seconds.
There aren't many hot hatches on the market right now that can match those figures (and there were less before 'right now').
Maximum power for the turbo four is available at 6000rpm with a 6700rpm redline, while the full 450Nm of torque is available between 2250 and 5000rpm.
With a twin-scroll turbocharger in play, peak pressure is listed at up to 140 bar, while maximum charge pressure is at 1.8 bar.
So, depending on how you measure it, the A 45 AMG could prove to be one of the most mental hot hatches ever to roll out of a factory and onto a public road. Legally.
Mercedes reckons it might also be one of the greenest, with the EU6 compliant engine listing fuel consumption at 6.9 l/100km and carbon emissions at 161g/km.
These figures again compare favourably to the 9.2 l/100km of the older five-cylinder mill in the RS 3, and 7.5 l/100km for the M135i.
Good numbers for what the German carmaker has declared the most powerful series production four-cylinder engine in the World.
"With the new A 45 AMG we have well and truly achieved our aim of developing the most dynamic, powerful and efficient four-cylinder series production car," AMG board member and vehicle development boss Tobias Moers said.
The new engine is also treated no differently to AMG's other powerplants, hand-built to the same "one man, one engine" philosophy applied to its eight- and 12-cylinder engines.
Along with the seven-speed automatic transmission - no manual is available - the A 45 AMG is equipped with Merc's 4Matic all-wheel-drive as standard.
While the requisite performance-focused tweaks feature, one crucial point in Mercedes' eyes is its weight: around 25 percent lighter than the system used in rival offerings (namely the quattro-equipped Audi RS 3).
As with other systems, the 4Matic package sees power sent to the front wheels in regular driving, while a 50:50 split is available "when driving dynamics so require".
There's also a speed-sensitive electromechanical dual pinion steering system, and braking is managed by 350x32mm discs at the front and 330x22mm discs at the rear. This all rides on 19x8 light alloy wheels, wrapped in 235/35 tyres.
The A 45 also gets a trick in its exhaust system, featuring the same automatic controlled exhaust flap featured with the SLK 55 AMG.
The flap is continuously adjusted by map control according to the power called up by the driver, load status and engine speed.
Watch for the A 45 AMG to make its world debut at next month's Geneva Motor Show.
Now, bring on the Black Series...
Speaking with TMR this week, Mercedes-Benz Australia's Jerry Stamoulis confirmed the A 45 AMG will make its local debut in the second half of 2013.
Specific timing, pricing and options will be confirmed closer to launch.
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