First a disclaimer. We are in no way positioning the A45 S as a cut-price alternative to a Porsche 911.
No matter what numbers the VBOX data logger spat out at the end of Heathcote’s strip, we all know that’s never going to be the case.
One is the most respected sports coupe in the world with over half a century of heritage behind it, and the other is a hatchback with a big turbocharger under the bonnet.
Nevertheless, we were curious to see just how quick the apex of the A-Class range would be when compared with base 911, albeit fitted with the optional Sport Chrono package.
Launch control engaged, both cars fire off from a standing start (no ego-massaging rollout here), the all-wheel-drive AMG matching the rear-drive 911 through 100km/h, banging through its first two gears in ultra-quick time.
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There’s still only a tenth in it to 170km/h whereupon the 911’s more slippery aerodynamics see it start to inch away.
We can put that down largely to aero, because the 911 is 27kW and 50Nm down on the car with the three-pointed star, albeit fractionally up on power-to-weight.
Time and again we repeated the sprints and the results were uncannily consistent. The first three runs for the AMG saw it hit 100km/h in 4.1, 4.0 and then 3.9 seconds. The results for the first trio of sprints for the 911? 4.1, 4.0 and 3.9 seconds.
None of the testers present had ever seen anything like it. At road legal speeds, at Heathcote on this day, the Porsche and the AMG were absolutely inseparable.
Over the longer 400m course, the Porsche tripped the beam in 12.1 seconds at 188.5km/h, while the A45 S came in a blink later at 12.2 seconds with 185.2km/h showing on the VBOX.
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Looking at some test data on record, the AMG’s 400m time is more than a second and a half quicker than the sharpest of the mere mortal hot hatches, the Honda Civic Type R, but lineball with the Audi RS3.
One measure where the lighter Porsche did gap the A45 S was in pure braking power. While the AMG is clearly no 911, it’s hard not to be impressed with this level of performance.
Because the launch control system is so simple and durable, these are figures that owners ought to be able to easily repeat. There’s no particular skill required: just follow the instructions, keep your foot in and the steering straight and that’s about it.
This means that in terms of real-world performance, there isn’t a muscle car sold that will reliably get the jump on the A45 S away from a set of lights. Only a modern supercar with launch control or a hot EV would be confident of gapping it. It’s that rapid.
Overall, Porsche manages to salve its pride on this occasion, and there are plenty of other reasons why you’d pay a premium for the 911, but the A45 S puts on a fearsome demonstration of its capability. How does it stack up on the road though? Find out here.
How they compare:
|Performance data||Mercedes-AMG A45 S||Porsche 911 Carrera|
|0-400m||12.2sec @ 185.2km/h||12.1sec @ 188.5km/h|
|Power-to-weight||185kW per tonne||188kW per tonne|
|Speed at indicated 100km/h||97||96|