Somehow we’re already halfway through 2024, and the automotive world is chugging along towards electrification. Pretty much every automaker offers multiple fully electric and hybrid models at this point, but there’s a distinct lack of plug-in versions of one particular body style: Convertibles. Aside from a few mid-engine supercars, almost no brands will sell you a convertible with anything beyond a simple 48-volt hybrid system. Mercedes is changing that with the 2025 Mercedes-AMG SL63 S E Performance, a plug-in-hybrid roadster with a long name and the performance to back it up.
Full disclosure: Mercedes flew me to Stuttgart, Germany to spend a few days driving the GT63 and SL63 PHEVs and riding along in the GT63 Pro. We stayed at some very nice hotels, and Mercedes put me up in a hotel in Amsterdam for two nights when the Crowdstrike outage canceled my flight home.
Underneath the skin the SL63 S E Performance is basically identical to the GT63 S E Performance. (For an even more in-depth take on this powertrain, read that review.) It pairs a twin-turbo 4.0-liter V8 engine over the front axle with an electric motor and battery pack mounted at the rear axle. On its own the engine makes 603 horsepower and 627 pound-feet of torque, 26 hp and 37 lb-ft more than the standard SL63’s V8. The electric motor puts out 201 hp and 236 lb-ft, with juice provided by the 6.1-kWh battery (of which 4.8 kWh is usable), and the motor can act directly on the driveshaft to power all four wheels. That 400-volt battery has a direct-cooling system featuring liquid that flows around all of the cells to cool them individually, so the pack is always at optimum temperature.
Add up all of the powertrain’s components and you’ve got a mega 805 horsepower and 1,047 lb-ft of torque. Mercedes estimates the SL63 S E Performance will reach 60 mph from a stop in just 2.8 seconds and go on to a top speed of 196 mph, making it both the quickest and fastest SL ever made. (Those figures are only 0.1 second and 3 mph off the GT, too.) It certainly feels that quick in practice; launch control is less brutal than in the gas-only SL, delivering a massive surge of torque that never lets up. It’s a phenomenal powertrain, with immediate response and strong acceleration no matter the speed or situation.
When the battery is fully charged the SL63 S E Performance will have an electric range of around 8 miles. In a world where other plug-in hybrids have EV-only ranges of upwards of 40 miles — including from Mercedes — that sounds low, even after hearing AMG engineers talk about how this powertrain is really about performance, not efficiency. In the real world, though, the car’s range is much greater.
In Sport mode, but especially the Sport+ and Race modes, the battery is always getting charged up as quickly as possible using the engine, belt generator and rear axle. The battery can be fully replenished in just a few minutes of normal driving, and the faster you go and harder you drive, the quicker it’ll fill back up. In these performance-oriented drive modes the car is still using that battery juice and electric motor to aid the engine in delivering maximum power, and yet the battery’s charge rarely dips.
Twist the drive mode knob into Comfort and the SL uses electric power for as long and as often as possible, but it won’t deplete the battery past about 25 percent. Even then, the car still turns off the engine as much as it can, and the operation is so seamless that I can barely tell when the engine kicks in. There’s an Electric drive mode too, which keeps the engine off until the battery runs out, unless you hit the kickdown point in the accelerator at which point the engine will kick in and the car automatically switches to Comfort. The electric motor can produce 94 hp of continuous output or the full 201 hp in peak situations, which is more than enough for around-town driving, and the SL will reach above 80 mph in Electric mode.
With the fabric roof stowed, which takes just 15 seconds and can be accomplished at up to 37 mph, the plug-in-hybrid system adds a whole new dimension to the SL that you don’t get in the GT. Snaking through quiet towns under electric power is wonderful. Easily peeved Germans just see the SL and smile as it silently glides past; if this were a normal SL63, they’d be scowling at the V8’s unnecessary noise at low speeds, which is doubly embarrassing with the top down. It starts up silently as well, using only battery power when the car is first turned on. As someone who rarely drives with the windows down let alone with convertible tops retracted, the EV operation made me actually want to drive the SL63 as a convertible. On the nice country roads around Mercedes’ Immendingen test facility, I can better hear the birds and smell the roses. Being able to glide around town silently makes it even better when I do want to switch it into Race mode and bring that lovely V8 to life.
And man, is it good in Race mode. The plug-in powertrain is super responsive and entertaining to rev out, and the V8 sounds awesome, with organic bangs and burbles. The SL’s handling is more playful than the GT’s, particularly when accelerating out of a corner where the car is a bit more squirrely and happier to kick the tail out a bit. Active hydraulic suspension with anti-roll stabilization keeps the car flat through corners, and rear-axle steering makes the handling more nimble than its near-5,000-pound weight would suggest.
One downside with Race mode is that you’re restricted to one of the softer regenerative braking settings. In any of the other modes, Electric included, the SL63 offers four levels of regen from none at all to one-pedal driving that can nearly bring the car to complete stop. (Above 65-percent battery charge the one-pedal mode is disabled, too.) It’s easy to get used to the strong regen, and the operation is linear even when going fast in the twisties — the transmission will even downshift aggressively when decelerating just using regen. The regen is blended in normal driving, but if you really stomp on the brake pedal the car relies on its massive carbon-ceramic friction brakes.
I must give a major shoutout to the spec of the SL I drove. Since its introduction in 2021 the new SL has always been available in some cool factory colors, but now Mercedes’ Manufaktur program offers a bunch of new colors and fancier interior options. This one is painted in Ireland Mid Green Magno, a satin-finish shade that is stunning in the sunlight and made even better when paired with all of the chrome exterior trim. A Manufaktur interior package covers more surfaces in colored leather, including the steering wheel, and you can finally get wood trim.
When the SL63 S E Performance reaches U.S. dealers later this summer it will start at $208,150 (including $1,150 destination), a premium of exactly $20,000 over the normal SL63. The PHEV is worth that upgrade to me, especially if you can plug in at home or live in the city. It doesn’t have much competition, either. A new Porsche 911 Carrera GTS T-Hybrid costs $180,195 (add $7,800 for AWD), though add any options and that rises fast. The 911 is a more pure sports car but without any electric-only range or plug-in capability. Maserati’s fully electric GranCabrio Folgore starts at $206,995, and while Andy says it’s really good, it’s a different proposition from the V8-equipped SL.
The biggest foil to the SL will be the facelifted Bentley Continental GT Speed, which has a PHEV setup with a V8 and 50 miles of electric range, though it’ll surely be a lot more money when it goes on sale later this. For now, if you want a droptop with an engine up front and some EV range, the 2025 Mercedes-AMG SL63 S E Performance is your car. Luckily it’s a good one.
