Mercedes-AMG GT63 knocks Porsche 911 GT2 RS from its perch

The Citizen

08-06-2025

600kW beast from Affalterbach clocks a new 0-100km/h record time of 2.76 seconds.
A plan was hatched. A team of the best of the best from the AMG Driving Academy, three half-decent driver/journalists, and an invaluable backup crew were going to invade Knysna with the latest in high performance Mercedes-AMG toys to attack the Simola Hillclimb with one goal in mind. Bring home the standard production road car, 2025 King of the Hill, title. Nothing less than a win would do.
And win they did, the fastest standard production road car up the hill this year was none other than AMG Driving Academy boss, Clint Weston, in the new Mercedes-AMG GT 63 S E Performance Coupe. But the team from Mercedes-Benz South Africa were not done. They were looking for more silverware for their trophy cabinet. One call later and the car that was fastest up the hill was on its way to Gerotek to see if it could become the fastest standard production road car The Citizen Motoring has ever tested in a straight line.
Gunning for Porsche's crown
To earn this title, the Mercedes-AMG GT 63 S E Performance Coupe, would have to better Porsche's 911 GT2 RS' record-breaking run of 2.85 seconds to 100km/h that was achieved in 2021. A quick technical refresher. The Porsche 911 GT2 RS weighs in at only 1 470kg, and produces a crazy 515kW and 750Nm from its 3.8-litre flat six, bi-turbo set-up. This means this out and out super car has a mental power-to-weight ratio of 350kW per ton.
ALSO READ: Eight-cylinders return as Mercedes-AMG prices long awaited SL 63
Producing a combined 600kW of power and 1 420Nm of torque from its 4.0-litre V8 bi-turbo engine that is coupled to an AMG Electric Drive Unit, the claimed 0-100km/h number for the Mercedes-AMG GT 63 S E Performance Coupe is listed as 2.8 seconds. And no Affalterbach series model has ever gone that quick before. Only one other car tested by our publication in over 25-years of road testing has gone under the three-second mark. The Mercedes-AMG GT 63 S E Performance 4-Door ran a time of 2.96 seconds.
Ready to roll. Picture: Mark Jones
Acid test for Mercedes-AMG GT63
Despite being down 20kW and 50Nm, the Coupe derivative has lost two doors and 185kg of weight over its four-door sibling. The team from Mercedes-Benz South Africa were confident their new car could get the job done. But the first issue to contend with is that this AMG GT 63 Coupe still comes off the scales an almost incomprehensible 725kg heavier than the GT2 RS. But talk and claims are cheap, it's what happens on the day that counts.
Driving the car out to Gerotek left me in no doubt that this GT 63 S E Performance Coupe was the real deal and had a proper chance of bettering the 911 GT2 RS. But even though I have been doing this a very long time, there is no way I could off the cuff say that the Merc was going to be quicker than the Porsche. 2.85-seconds to 100km/h is seriously fast. With anticipation building, the Racelogic VBOX test equipment was loaded into the car and it was time to head down to the start line.
ALSO READ: VIDEO: New Mercedes-AMG C63 pips BMW M3 on the drag strip
Getting down to business
Race Start activated, foot on the brake, mash the accelerator pedal, and let go. The Mercedes-AMG GT 63 S E Performance Coupe bolts off the line like its tail has just been stood on. Shrubbery, grass and tar merge into a blur as the speedo goes past 270km/h before I get on the carbon ceramic brakes at the 800m mark. Heart pounding, adrenalin rushing, the VBOX readout shows 2.86 seconds.
We haven't done it. It goes a bit quiet, we know we will do more runs. But all these super high-performance cars get hot under the hood quickly, and the numbers can go the other way. Is it over?
Back down to the start I go. Cut and paste the start procedure. Back on the brakes at the end. And as I roll into the pit area. It goes off like a cracker, we have a number of 2.84 seconds on the VBOX. It is done.
The GT 63 S E Performance Coupe has just become the fastest standard production road car we have ever tested. Albeit by a whisker. But a whisker is all that is needed for the record books.
ALSO READ: Learjet for the road Mercedes-AMG S63 shocks-up a luxury storm
Point proven
Obviously, we wanted to back this up, the Porsche did, so it was back down to the start again where things only got better as the tyres warmed up a little with all this winter cold around. A 2.82-second run was next, then a 2.78 and then 2.76. Were we going to see the records continue to tumble?
There is a new boss in time. Picture: Mark Jones
The short answer was no. The temps under the bonnet were now coming into play and the times started going back up. But I kid you not, the car did five runs in a row after this at 2.84-seconds. And that's when we decided we had proved our point. We were tempting fate by barrelling into the braking zone over and over again at 270km/h.
So, there you have it, the GT 63 S E Performance Coupe is the fastest standard production we have tested. The Porsche 911 GT2 RS does come back at it as we head further down the long straight at Gerotek, and it remains a do-or-die battle right till the end, but there can only be one King.
Mercedes-AMG GT 63 tests data