Mercedes-AMG SL 63 vs Porsche 911 Turbo S
Compare the Mercedes-AMG SL 63 vs Porsche 911 Turbo S. The Mercedes-AMG SL 63 is £10,000 cheaper. The Porsche 911 Turbo S is 0.9s quicker to 60mph. The Mercedes-AMG SL 63 is more fuel efficient. Full performance, cost & ownership breakdown.
The Mercedes-AMG SL 63 is priced from £165,000, powered by a 4.0L Twin-Turbo V8, producing 577 hp, with 800 Nm of torque, reaching 0-60 mph in 3.5s, a top speed of 196 mph, sent to the road via all-wheel drive. The Porsche 911 Turbo S is priced from £175,000, powered by a 3.8L Twin-Turbo Flat-6, producing 640 hp, with 800 Nm of torque, reaching 0-60 mph in 2.6s, a top speed of 205 mph, sent to the road via all-wheel drive.
The Mercedes-AMG SL 63 offers a 213-litre boot, runs on petrol, returns around 24 mpg, is covered by a 3yr / unlimited mi warranty. The Porsche 911 Turbo S offers a 128-litre boot, a usable front boot, runs on petrol, returns around 20 mpg, is covered by a 4yr / 50k mi warranty.
On cost of ownership, the Mercedes-AMG SL 63 is £10,000 cheaper than its rival, the Mercedes-AMG SL 63 costs less in annual maintenance (£1,500 versus £1,800), the Mercedes-AMG SL 63 is the more fuel-efficient choice, a full tank costs around £90 for the Mercedes-AMG SL 63 and £90 for the Porsche 911 Turbo S.
Driving Character: Mercedes-AMG SL 63 vs Porsche 911 Turbo S
The Mercedes-AMG SL 63 transitions the lineage toward a sophisticated grand tourer profile, prioritising compliance over the surgical precision of its predecessor. The 4.0-litre twin-turbo V8 delivers a relentless surge of torque, managed by an all-wheel-drive system that ensures composure in challenging UK conditions. While the AMG Active Ride Control suspension offers remarkable poise for a heavy convertible, the steering feel remains somewhat insulated compared to pure sports cars. It excels as a high-speed cruiser rather than a track-day weapon, favouring long-distance refinement and effortless pace over the frantic, razor-sharp feedback once associated with the AMG brand.
The Porsche 911 Turbo S utilises a sophisticated AWD system with active torque vectoring that provides staggering, all-weather performance. It feels deceptively rapid, with a chassis control system that masks its immense power through cornering, yet it ultimately insulates the driver more than the GT-spec siblings, prioritizing crushing point-to-point speed over nuanced steering feel.
Head-to-head, the division is clear: the Porsche 911 Turbo S takes our 0-100 driving character grading, 78 against 88. Characteristic of the Mercedes-AMG SL 63: Composed, quattro-like AWD grip with genuine open-top GT character. For the Porsche 911 Turbo S: Immense, effortless all-wheel-drive pace with real depth of ability. In outright terms it is 577 hp against 640 — a 63 hp gap — and the Porsche 911 Turbo S reaches 60 mph 0.9s sooner.
Interior & Cabin: Mercedes-AMG SL 63 vs Porsche 911 Turbo S
Inside, the SL 63 feels thoroughly modern, dominated by a portrait-oriented MUX interface that dictates the cabin aesthetic. The digital cockpit is crisp, though the heavy reliance on touch-sensitive surfaces can feel counterintuitive when pressing on. Material quality is excellent, with high-grade leathers and metals, yet the ergonomics are compromised by the vestigial rear seats, which serve more as shelf space than viable seating. It lacks the intimate, driver-focused cocoon of the previous AMG GT, opting instead for a broad, open-air cockpit design that prioritises perceived luxury and connectivity over raw, tactile immersion.
The cabin is remarkably refined for such a potent machine, making it a genuinely usable daily GT car. It features the signature Sport Chrono dial and luxury seating, with all technology packages seamlessly integrated. While the material quality is high, it lacks the bespoke flair or artisanal material choices found in certain Italian rivals at this price point.
Head-to-head, the division is clear: the Mercedes-AMG SL 63 takes our 0-100 interior & cabin grading, 85 against 84. Characteristic of the Mercedes-AMG SL 63: Luxurious, modern cabin with excellent build quality. For the Porsche 911 Turbo S: Supportive, comfortable seats and modern, user-friendly cabin.
Daily Usability: Mercedes-AMG SL 63 vs Porsche 911 Turbo S
Daily utility is remarkably improved, largely due to the transition to a fully variable fabric roof that saves significant boot space and lowers the centre of gravity. The 213-litre capacity remains tight, though it accommodates soft luggage better than the old hard-top systems. Parking remains a chore; the wide, low-slung bodywork requires cautious navigation through tight urban gaps, and the extensive bonnet length demands foresight. Nevertheless, the sophisticated suspension tuning allows it to soak up poorly maintained road surfaces with grace, making it a viable, albeit thirsty, companion for regular motorway commutes and long-distance touring.
As the most practical 911 variant, the Turbo S offers genuine all-season confidence thanks to its AWD architecture. Its clever combination of a front boot and rear storage allows for meaningful luggage space, though the expansive body width can create significant challenges in tight urban environments. Furthermore, its sheer performance demands regular attention to tyre wear.
Head-to-head, the division is clear: the Porsche 911 Turbo S takes our 0-100 daily usability grading, 68 against 90. Characteristic of the Mercedes-AMG SL 63: Comfortable, capable long-distance convertible for daily use. For the Porsche 911 Turbo S: The most daily-usable supercar on sale — comfortable, quiet, easy to place. that means 213 litres of boot space against 128, plus a usable front boot in the Porsche 911 Turbo S, and everyday running costs that favour the Mercedes-AMG SL 63 at the pumps.
Ownership: Mercedes-AMG SL 63 vs Porsche 911 Turbo S
Ownership is bolstered by the vast, well-integrated Mercedes-Benz dealer network, which provides consistent support for the complex AMG powertrain. Maintenance costs are steep, with annual services reflecting the performance-oriented nature of the twin-turbo V8, and the intricate soft-top mechanism introduces a long-term servicing variable that owners must anticipate. While depreciation is generally mitigated by the enduring prestige of the SL moniker, the market is competitive. Reliability is generally predictable, provided the rigid servicing intervals are respected, ensuring the complex electronics and drivetrain remain within optimal operating parameters throughout the ownership period.
Maintaining a stellar reputation for reliability, this model remains a benchmark for high-performance usability. It commands premium residuals in the used market, consistently holding its value well. However, prospective owners must account for high annual maintenance costs, with the complex PDK transmission and AWD system adding significant weight to long-term service intervals compared to simpler sports cars.
Head-to-head, the division is clear: the Porsche 911 Turbo S takes our 0-100 ownership grading, 68 against 88. Characteristic of the Mercedes-AMG SL 63: Backed by Mercedes-AMG's established reliability record. For the Porsche 911 Turbo S: Exceptionally reliable for a car with supercar performance. On the wallet the two diverge at £165,000 versus £175,000 — a £10,000 difference, with annual maintenance of £1,500 against £1,800, and warranty cover of 3yr / unlimited mi versus 4yr / 50k mi.