IMMENDINGEN, Germany – After dominating the Autobahn with the GT 63 SE Performancewe took a detour into the lush, rolling South German countryside. It wasn’t just to shake things up. There, in the forest just outside the small town of Immendingen, lay a Mercedes test facility and the brief opportunity to test the 2025 Mercedes-AMG SL 63 SE Performance.
And by short, we mean it – two half-hour drives on winding country roads around the facility, plus some slow driving through villages. No Autobahn and no fast drives at the “Prüf- und Technologiezentrum” either. It wasn’t much time, but the good news is that the SL 63 SE Performance is essentially a convertible GT 63.
The powertrain is identical, including the 4.0-liter twin-turbo V8, nine-speed automatic transmission, 4Matic+ all-wheel drive and a rear-mounted engine fed by a 6.1-kilowatt battery pack and sent through a two-speed rear-end transmission. The SL 63 SE Performance makes the same 805 horsepower and 1,047 pound-feet of torque as the GT version, plus the same estimated 8 miles of electric range in European tests. It’s just a tenth of a second slower to 60 mph (2.8 seconds) and 3 mph slower at top speed (196 mph).
The similarities don’t stop there. The two car sharing same width and wheelbase, are nearly the same length (the SL is just over half an inch shorter), and the interiors are basically the same. Rear-axle steering, carbon ceramic brakes and the trick Active Ride Control suspension are all standard, too. The SL is essentially a GT convertible with a different front fascia and a center screen that tilts to reduce glare with the top down.
So pretty much everything we said about the GT 63 applies to the SL, too. But there are, admittedly, some differences. The biggest one, well, aside from that fabric roof, is the suspension setup. While it also gets the Active Ride Control suspension (along with a variety of hugely complex elements, the adaptive dampers are hydraulically linked), the setup is a touch softer across the board than the GT’s. It’s not a dramatic difference – the SL is nearly as agile on the road as the GT – but it’s enough to imply that the SL is intended to be a little more relaxed. It sacrifices that little bit of responsiveness for a touch less harshness. This shift in character also helps make the slightly rakish steering much more forgivable.
So what we have is the GT, but a little more relaxed. That may be a reason for some, but ultimately we are left with a less intense version of a car that we decided was not intense enough given its enormous power. It almost seems wasted, even more so in the SL. The 577 hp, non-hybrid SL 63 offers more than enough power, making the 805-hp SE Performance overkill, and not necessarily in a fun, Hellcat-like way. A noisy AMG The V8 will sound just as growly with the hood down, regardless of whether the car has an electric motor or not.
What the non-hybrid can’t offer is peaceful, quiet, top-down cruising. As much fun as it was to hear that V8 echo through the German hills, it was equally delightful to let those pipes fall silent and just enjoy the wind rushing past as the sun set. The sleepy villages we silently cruised through probably didn’t mind either. And as we discussed earlier, the engine’s 200 horsepower is more than enough to lug around, even at highway speeds.
But then we ran into the same problem as before: you can hardly get anywhere on electric power. In no time you’ve sucked that small, all-electric range dry and you have to keep the V8 running to charge the pack. And that’s assuming you’ve charged it beforehand.
As with the GT, we’re left wondering whether the powertrain is fit for purpose. In the GT, it seemed like the car had a ton of power, but wasn’t made sporty enough to make the most of it. In the case of the SL, it seems like Mercedes didn’t go far enough with electrification. The electric function is very appealing, but the range is so poor that it’s almost pointless for weekend getaways, let alone everyday use. And since it’s not a maximum-attack sports carIt would have been nice if Mercedes had focused more on range and capacity, rather than rapid discharge and power. In that respect, it leaves us longing for an all-electric SL.
There’s one thing we know about the SL that we don’t know about the GT: the price. Base pricing for the SL 63 SE Performance starts at $208,150. That’s a fairly similar price jump between the SL 55 and the SL 63, and for a much bigger increase in power. So at least in terms of power per dollar, it’s not a bad deal.
If you want the most SL, the SE Performance is undoubtedly the best choice. And it’s still a handsome, comfortable, fast machine, one that’s reasonably priced considering what it adds on paper. But what it adds in terms of experience is more questionable. Its V8-only siblings offer almost all of the experience on petrol, while its own electrified benefits are negligible. It’s a contradiction, and as a result, so are we.