Mercedes-AMG SL63 (R231, 2017-2020) review

The AMG SL63 is Mercedes’ principal beach-side cruiser that, in true hot rod style, has been bestowed with a hugely powerful engine. Unlike traditional hot rods though, the engineers at Affalterbach have gone to town with the rest of the car giving it trick suspension, a suitable drivetrain and a super stiff shell. This AMG might shatter the dowdy reputation the SL once had.

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Engine, gearbox and 0-60mph

With 577bhp and 664lb ft of torque the SL63 certainly isn’t lacking in performance. It will reach 0-62mph in 4.1 seconds. Even more impressive when you know it weighs 1770kgs.

The engine sounds hilarious. On start-up, there’s a big whumpf from the exhaust and the whole car shudders. Its low grumble at idle really helps the SL63 feel like a hot rod but as soon as the revs rise the engine starts to emit a noise that’s a lot angrier. It spits out exhaust gasses and sounds more like gunfire than a V8. On over-run there’s even more drama, with pop, crackles and the occasional bang. Every now and then you hear a whistle or chirp from the turbos, but most of the time the exhaust noise drowns all that out.

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The SL63, unlike every other SL in the range (SL400, SL500 and SL65), gets AMG’s multi plate, wet clutch, 7-speed transmission. Its shifts are quicker and sharper than those of a traditional automatic gearbox with a torque converter but not quite as crisp as a double clutch transmission.

With the all that torque though, a 7-speed gearbox seems somewhat overkill. It can accelerate in almost any gear. Yes, it is far more savage in the lower gears but the engine revs so quickly, and only revs to just under 6500rpm, that you hit the limiter before you know it. It’s best just to keep it in a higher gear.

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Technical highlights

The SL has Active Body Control (ABC), a system that replaces traditional antiroll bars with an oil filled unit above each of its 4 springs. The system reacts to road conditions and driver inputs to reduce body movements during cornering, braking and accelerating. It does this by pumping more oil into the ABC units where there might be excess lean. For example, more oil will be pumped to the back during acceleration to stop the back squatting down.

The system can go even further and actually lean the car into the bends, but this isn’t available on the AMG models, just the SL400 and SL500. It’s a clever system but when driving quickly, the tilting effect can feel unnatural.

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What’s it like to drive? 

We’ve concluded, thanks to its engine, the SL63 is certainly fast. However, its ride is very comfortable most of the time, making high speeds feel relaxed. There are four pre-programmed settings that alter the way the car feels: Comfort, Sport,  Sport+ and Race. In anything but Race the ride was perfectly fine for the southern Californian roads the test was on. Sport and Sport+ adding a pleasing amount of control to the body and less roll than the in Comfort mode.

The largely aluminium shell feels incredibly stiff. Occasionally, in the firmer suspension modes, if one wheel gets a particularly nasty jolt there’s a bit of an unwanted shudder from the car, but for the most part it’s hugely impressive.

The steering is also changed by the different driving modes, however none of the settings seemed to eradicate a feeling of stickiness around the dead-ahead position. Once a bigger in-put was made the steering did lighten up, but sadly never started to relay any sort of feedback.

The steering is quick, and when you enter a corner you can easily add too much lock. Both the absence of feel from the steering and the lack of roll in the body mean its difficult gauge how much steering you’ll need. This can easily push the SL into understeer on turn-in. However, once you’re used to the rate of the steering and you’ve learnt you need to be patient at the start of the corner, the SL really comes together.

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There’s a lot of traction and despite the huge amount of torque, it’s not easy to unstick the rear wheels even when driving quickly. However when pushing hard, especially in Sport+ mode, the window between the tyres gripping and completely spinning feels vast. From mid-corner onwards your line can be adjusted with the throttle, with more throttle pushing the car into oversteer. Not heroic tyre-smoking oversteer, not even enough to require any perceptible opposite lock, but just the right amount to make you feel like you’re controlling the car with the rear axle. The SL63 displays how entertaining the inherent balance and predictability of a front-engined rear wheel drive car can be.

It’s easy to get carried away once you’re used to the SL. The ABC suspension really helps disguise just how heavy the car is, but if you keep pushing hard the brakes will eventually remind you. After driving quickly through a down hill section, the brake pedal travel increased a fair amount. There was always enough brake force to slow the car sufficiently but, when there’s a significant drop next to the road, anything but perfect brakes sure can knock your confidence. The car I tried was on the standard cast iron brakes, had it had the optional carbon ceramics it may not have been a problem.

How does it compare? 

The SL63’s closest rival is probably the Ferrari California T. Both have turbocharged V8s, and folding metal roofs but the Ferrari is more exotic. We haven’t been blown away by the Califonia’s dynamics, but a new Speciale handling pack coming soon might change that.

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However, Aston Martin’s V12 Vantage Roadster might be the one to beat. It is getting on a bit now but it’s still one of the best looking cars you can buy. Its V12 engine is glorious and its chassis is extremely well balanced.

The SL63 has some tough competition, but it's abilities mean it's equiped to put up a good fight. 

Specs