The Mercedes-AMG A 45 4Matic has never wanted for sheer speed or dynamic ability, but this upgraded model clearly raises the bar in both departments, making it an even more enticing and accomplished car to drive, whether on public roads or a race track.
The engine remains the undisputed highlight, now feeling even more muscular and determined than before on a pegged throttle in lower gears. Smoother qualities at the lower end of the dial and a more resolute feel through the mid-range also provide the new A 45 with a wonderfully effortless feel when hauling taller ratios at constant cruising speeds.
The 376bhp power peak provides a power-to-weight ratio of 242bhp per tonne – 15bhp per tonne more than its keenest rival, the latest Audi RS3.
Mercedes-AMG claims the sprint to 62mph now takes just 4.2sec, which is a scant 0.1sec inside the time quoted by Audi for the RS3. To put this into perspective, the newly facelifted Porsche 911 Carrera hits the same mark in a claimed 4.6sec.
Significantly, the boost in performance does not come at the detriment of economy, which remains highly impressive. The official combined figure of 42.2mpg is the same as that quoted for the original A 45, endowing it with average CO2 emissions of 161g/km.
Accompanying the increase in raw speed delivered by the upgraded driveline is a noticeable improvement in straight-line stability. With subtle aerodynamic upgrades, including an optional rear wing that comes as part of an AMG aerodynamic package to provide a reduction in lift, the new A45 tracks with enhanced poise all the way to its 155mph top speed. The rear end is now particularly well tied down at higher speeds.
As accomplished as it is in a straight line with its throttle against its stop on a lightly trafficked autobahn, it is the way the A 45 delivers over a challenging back road that really raises eyebrows. Few cars at any price are so swift yet as accommodating from point to point on the road. Its sheer effectiveness, no matter what the weather conditions, places it ahead of many big-name supercars for outright dynamic prowess.
Grip levels are colossal. It takes a huge cornering speed to unseat the stunning purchase of the 225/40 18 front tyres, either in the dry or wet. The inherent firmness of the dampers in anything but Comfort mode also endows the A 45 with rock-solid body control on smooth roads. There’s some roll, but it never impedes progress.
We’ll have to wait to see how it responds with a typical British B-road, but the reworked underpinnings clearly deliver improved impact qualities, so it is less prone to being thrown off line by mid-corner bumps when you’re really charging. There are also lower levels of tyre roar, making this facelifted A 45 a more accomplished longer-distance proposition.
A rotary dial on the centre console offers the choice between Comfort, Sport, Sport Plus and Race modes, providing it with distinctly different properties in each setting. As well as altering the damping qualities, a Dynamic Select system alters the characteristics of the throttle, gearbox, steering and damping.
The inclusion of adaptive damping serves to broaden the dynamic envelope, allowing you to dial up a far more cosseting ride than before. Greater levels of compliance have been introduced to its previously unrelenting chassis, making the A 45 a more acceptable proposition in town than before.
If there is a criticism to be level, it is the vague feel imparted by its electro-mechanical steering. There is genuine feel during initial turn-in and the overall weighting is well judged. However, there is a lack of feedback off-centre as lock is increased.