The Mercedes-AMG SL63 was already a powerhouse, but the SL63 S E Performance takes it to a whole new level. This hybrid marvel is not only packed with cutting-edge technology but also delivers a staggering performance that will leave you breathless, all while maintaining its grand touring charm.

With the previous iteration of the SL63, its 430 kW engine was more than sufficient to leave most competitors in the dust. Yet, Mercedes-AMG has pushed the envelope further with the E Performance variant. This model introduces a rear-mounted hybrid motor, adding an extra 170 kW to the mix. Combined with the twin-turbo V8, the total output now stands at a jaw-dropping 600 kW and 1,420 Nm of torque. These figures, once the realm of hypercars, are now a reality for this iconic convertible.

The transition to hybrid power hasn't compromised the SL's aesthetics. This is arguably the best-looking SL since the early 2000s R230 generation. The return to a cloth soft top enhances its sleek profile, steering clear of the bulkiness that plagued the previous power-folding hard tops. The car's proportions are spot on, and its aggressive yet elegant front fascia is a head-turner.

However, all this hybrid tech does add some heft. The standard SL63 tips the scales at 1,960 kg, and the hybrid gear adds roughly 225 kg more. You can feel the weight, especially when navigating tight corners. It's almost in the mid-size truck territory when it comes to heft, but thankfully, AMG's Active Ride Control suspension helps mitigate this. The system, which forgoes traditional sway bars for hydraulically linked dampers, adjusts each corner individually to balance comfort and handling.

During my brief drive on Germany's smooth back roads, the suspension felt impressive. Given its performance in models like the GT63 and G63, I have no doubt it can handle less pristine roads with equal aplomb.

The drivetrain is a masterpiece. The 4.0-liter twin-turbo V8, paired with the rear-mounted electric motor, produces an exhilarating 600 kW and 1,420 Nm of torque. The response is instantaneous, thanks to the electric motor’s 150 kW available from zero rpm, bridging any turbo lag seamlessly. The result is a relentless surge of power that feels like a continuous wave of thrust, much like a pure electric vehicle but without any fall-off at higher speeds.

While I didn’t get to fully unleash the SL63's potential on the Autobahn, I have no reason to doubt its capability. I hit 308 km/h in the GT63, and the SL63 feels equally poised to reach such speeds. It’s blisteringly fast, yet remains composed and comfortable – a true grand tourer with supercar credentials.

Despite its weight, the SL handles corners with remarkable grace. The steering is razor-sharp, with minimal input needed to guide the car's nose into bends. It's a touch softer and less responsive than the GT63, but that suits the SL's character as a luxury cruiser rather than an all-out sports car.

The interior, however, is a mixed bag. Almost every function is controlled through an 11.9-inch portrait touchscreen. While drive modes and entertainment settings are straightforward, climate controls trapped in a digital interface can be frustrating. The lack of a physical volume knob and the finicky touch-capacitive buttons on the steering wheel further detract from the user experience. It’s a learning curve, and even then, not as intuitive as traditional buttons. At least the seats offer exceptional comfort.

With a starting price north of €180,000, the interior's quirks are harder to overlook. However, the SL63 S E Performance redeems itself with its phenomenal acceleration and performance. A few full-throttle sprints will quickly make you forget the interface woes.

The additional 150 kW from the electric motor transforms the SL63 from a luxury convertible into a bona fide rocket ship. It combines spine-tingling speed with refined cruising, making it a unique proposition in the high-performance luxury segment.