Somehow we’re halfway through 2024, and The automotive world is moving towards electrification.. Almost every automaker offers a variety of all-electric and hybrid models at this point, but they lack a plug-in version of one particular body style: the Convertible. Besides some mid-engine supercarsHardly any brand will sell you a convertible with anything more than a simple 48-volt hybrid system. Mercedes is changing that with Performance of the 2025 Mercedes-AMG SL63 SEA plug-in hybrid convertible with a long name and performance worthy of the name.
Full disclosure: Mercedes flew me to Stuttgart, Germany to spend a few days driving the GT63 and SL63 PHEV, and also a ride in the GT63 Pro. We stayed at some very nice hotels, and Mercedes arranged for me to stay at a hotel in Amsterdam for two nights when the Crowdstrike incident canceled my flight home.
Under the skin, the SL63 SE Performance is essentially identical. GT63 SE Performance(For more details on this powertrain, read that review.) It pairs a twin-turbocharged 4.0-liter V8 on the front axle with an electric motor and battery pack mounted on the rear axle. The motor alone produces 603 horsepower and 627 pound-feet of torque, up 26 horsepower and 37 pound-feet from the SL63 standard‘s V8. The electric motor makes 201 horsepower and 236 lb-ft of torque, with power provided by a 6.1 kWh battery (of which 4.8 kWh is usable), and the motor can drive the driveshaft directly to power all four wheels. That 400-volt battery has a direct-cooling system with liquid flowing around all the cells to cool each one individually, so the battery pack stays at its optimal temperature.
Add all the powertrain components together, and you get a whopping 805 horsepower and 1,047 lb-ft of torque. Mercedes estimates the SL63 SE Performance will hit 60 mph from a standstill in just 2.8 seconds and reach a top speed of 196 mph, making it the quickest and fastest SL ever built. (Those numbers are just 0.1 second and 3 mph slower than the GT.) It’s certainly that quick in practice; the launch control is less brutal than the gas-only SL, creating a never-ending stream of torque. It’s a phenomenal powertrain, with instantaneous response and strong acceleration regardless of speed or situation.
With a fully charged battery, the SL63 SE Performance will have an electric-only range of about 8 miles. In a world where other plug-in hybrids have EV-only ranges of more than 40 miles—including the Mercedes—that sounds low, even after hearing AMG engineers talk about how this powertrain is really about performance, not efficiency. But in the real world, the car’s range is much greater.
In Sport mode, but especially Sport+ and Race mode, the battery is always charged as quickly as possible by the engine, belt alternator and rear axle. The battery can be fully charged in just a few minutes of normal driving, and the faster and harder you drive, the faster the battery will recharge. In these performance-focused driving modes, the car still uses battery power and the electric motor to assist the engine in delivering maximum power, but the battery charge level rarely drops.
Turn the drive mode dial to Comfort and the SL will run on electric power as long as possible and as often as possible, but it won’t drain the battery past 25 percent. Even then, the engine will shut off as much as possible, and it does so seamlessly that I barely noticed when it started. There’s also an Electric drive mode, which will keep the engine off until the battery is depleted, unless you hit the kickdown point on the accelerator, at which point the engine kicks in and the car automatically switches to Comfort. The electric motor can produce 94 horsepower continuously or a full 201 horsepower in peak situations, which is more than enough for around-town driving, and the SL will hit speeds in excess of 80 mph in Electric mode.
With the fabric top down, which takes just 15 seconds and can be done at speeds of 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. It’s a joy to weave through quiet towns on electric power. The irascible Germans just look at the SL and smile as it glides by silently; a normal SL63 would frown at the unnecessary low-speed hum of the V8, which is doubly embarrassing with the top down. It also starts silently, using only battery power when first switched on. As someone who rarely drives with the windows down, let alone with the convertible top retracted, the EV action makes me want to actually drive the SL63. like a convertible. On the beautiful country roads around Mercedes’ Immendingen test facility, I could hear the birds singing and smell the roses more clearly. Being able to glide around town with ease made it even better when I wanted to switch to Race mode and bring that lovely V8 to life.
And man, it’s great in Race mode. The plug-in powertrain is super responsive and fun to drive, and the V8 sounds great, with organic pops and rumbles. The SL’s handling is more playful than the GT’s, especially when accelerating out of corners, where the car squirms and likes to kick the rear end out a bit. The active hydraulic suspension with anti-roll stabilization keeps the car level in corners, and the rear-axle steering makes for nimble handling that belies its nearly 5,000-pound curb weight.
One downside to Race mode is that you’re limited to one of the softer regenerative braking settings. In every other mode, including Electric, the SL63 offers four levels of regen, from none at all to one-pedal driving that can almost bring the car to a stop. (Above 65 percent battery charge, one-pedal mode is also disabled.) It’s easy to get used to the strong regen mode, and it works linearly even when driving fast on winding roads—the transmission will even downshift hard when decelerating with just the regen mode. The regen mode is mixed in during normal driving, but if you really hit the brakes, the car relies on its big carbon-ceramic friction brakes.
I have to give a big shout out to the specification of the SL I drove. Since its launch in 2021, the new SL has always been available in some gorgeous factory colours, but now Mercedes’ Manufaktur programme offers a range of new colours and more luxurious interior options. This car was painted in Irish Mid Green Magno, a satin finish that looks stunning in the sunlight and even more beautiful when paired with all the chrome exterior trim. The Manufaktur interior package covers more surfaces in coloured leather, including the steering wheel, and you can finally get wood trim.
When the SL63 SE Performance arrives in U.S. dealerships later this summer, it will start at $208,150 (including $1,150 destination), a full $20,000 premium over the regular SL63. To me, the PHEV is worth that upgrade, especially if you can plug in at home or live in the city. It also doesn’t have much competition. One Porsche 911 Carrera GTS T-Hybrid The 911 starts at $180,195 ($7,800 more for AWD), though add any options and the price will quickly rise. The 911 is a purer sports car, but it lacks electric-only range or plug-in capability. Maserati’s all-electric GranCabrio Folgore It starts at $206,995, and while Andy says that’s a really good price, it’s still a step up from the V8-powered SL.
SL’s biggest shield will be Bentley Continental GT Speed upgraded versionhas a PHEV setup with a V8 and a 50-mile electric range, though it will certainly be much more expensive when it goes on sale later this year. For now, if you want a front-engined convertible with some electric range, the 2025 Mercedes-AMG SL63 SE Performance is the car for you. Luckily, it’s a good one.
