Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4
Compare the Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4. The Porsche 718 Cayman GT4 is £0 cheaper. The Mercedes-AMG C 63 S Saloon is 0.4s quicker to 60mph. The Mercedes-AMG C 63 S Saloon is more fuel efficient. Full performance, cost & ownership breakdown.
The Mercedes-AMG C 63 S Saloon is priced from £55,000, powered by a 4.0L Twin-Turbo V8, producing 503 hp, with 700 Nm of torque, reaching 0-62 mph in 4 s, a top speed of 180 mph, sent to the road via rear-wheel drive. The Porsche 718 Cayman GT4 is priced from £84,000, powered by a 4.0L Flat-6, producing 414 hp, with 420 Nm of torque, reaching 0-62 mph in 4.4 s, a top speed of 188 mph, sent to the road via rear-wheel drive.
The Mercedes-AMG C 63 S Saloon offers a 435-litre boot, folding rear seats, runs on petrol, returns around 26 mpg, is covered by a 3 years / unlimited miles (original UK new-car cover) warranty. The Porsche 718 Cayman GT4 offers a 150-litre boot, a usable front boot, runs on petrol, returns around 25 mpg, is covered by a 3 years / unlimited miles (original UK new-car cover) warranty.
On cost of ownership, the Porsche 718 Cayman GT4 is £0 cheaper than its rival, both require around £1,100 per year in maintenance, the Mercedes-AMG C 63 S Saloon is the more fuel-efficient choice, the Porsche 718 Cayman GT4 has 64 L fuel tank.
Driving Character: Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4
The W205 facelift C 63 S Saloon combines a 375 kW V8 with rear-wheel drive. Its MCT gearbox uses a wet start-off clutch. Adaptive damping and an electronic rear differential support its performance character. This entry represents the petrol V8 saloon.
The Porsche 718 Cayman GT4 is the definition of chassis purity, pairing a naturally aspirated 4.0-litre flat-six with a mid-engine layout that offers near-perfect neutrality. The 414hp delivery is linear and predictable, allowing for precise throttle modulation through technical sections of track. The manual gearbox is a highlight, featuring short, mechanical throws that engage the driver completely. While it lacks the raw top-end speed of 911-based variants, the balanced chassis and communicative steering allow it to carry immense cornering speed, making it an exceptionally rewarding tool for those who value driver input over outright power figures.
Head-to-head, the division is clear: the Mercedes-AMG C 63 S Saloon — 4.0-litre twin-turbo V8 and rear-wheel drive; the Porsche 718 Cayman GT4 — 4.0L naturally aspirated flat-six; mid-engine architecture provides exceptional balance during corner entry. Characteristic of the Mercedes-AMG C 63 S Saloon: Nine-speed MCT gearbox and electronically controlled rear differential. For the Porsche 718 Cayman GT4: Direct steering response; high-grade chassis hardware encourages precise lines on technical circuits. In outright terms it is 503 hp against 414 — a 89 hp gap — and the Mercedes-AMG C 63 S Saloon reaches 60 mph 0.4s sooner.
Interior & Cabin: Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4
The cabin follows the W205 dashboard layout. It uses a separate central infotainment display and centre-console controls. Trim and seat specifications depend on equipment. Portrait MBUX and W206 hybrid descriptions have been removed.
The cabin prioritises function, stripping away unnecessary luxuries in favour of an Alcantara-lined environment that feels race-ready. The Sport Seats Plus provide excellent lateral support during spirited driving, while the minimalist dashboard design ensures the focus remains entirely on the road ahead. Given its track-focused intent, the cabin storage is sparse and the rear seating area is replaced by a structural strut brace. It is a clean, purposeful space, though some may find the lack of comfort-oriented features a challenge for long-distance touring, fitting perfectly with the model's lightweight, enthusiast-oriented persona.
Head-to-head, the division is clear: the Mercedes-AMG C 63 S Saloon — Four-door W205 cabin with separate central display; the Porsche 718 Cayman GT4 — Ergonomic control placement; steering wheel diameter and shifter position offer natural driver connection. Characteristic of the Mercedes-AMG C 63 S Saloon: Facelift instrument and steering-wheel controls; equipment varies by car. For the Porsche 718 Cayman GT4: Alcantara upholstery and brushed aluminium; functional cabin design favours long-term material durability.
Daily Usability: Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4
The UK specification lists a 435-litre boot. The four-door body supports daily passenger use. This V8 model has no plug-in charging or electric-only mode.
Utility is a standout feature, as the combination of front and rear trunks allows for surprising storage capacity, making the GT4 a versatile choice for weekend touring. Its compact dimensions make it relatively easy to navigate through tight city streets, although the low front splitter demands care over speed bumps and steep inclines. The suspension is firm, bordering on harsh for daily use in Sport mode, though it remains composed enough for the committed driver. It manages to balance track-ready performance with sufficient real-world practicality, provided the owner is prepared for a more rigorous ride quality.
Head-to-head, the division is clear: the Mercedes-AMG C 63 S Saloon — Five-seat saloon layout and 435-litre boot; the Porsche 718 Cayman GT4 — Dual luggage compartments; combined 150L boot and front trunk facilitate extended touring capability. Characteristic of the Mercedes-AMG C 63 S Saloon: 11.8-metre turning circle in the UK brochure. For the Porsche 718 Cayman GT4: 115 mm ground clearance provides utility; ride quality remains acceptable for occasional spirited driving. that means 435 litres of boot space against 150, plus a usable front boot in the Porsche 718 Cayman GT4, and everyday running costs that favour the Mercedes-AMG C 63 S Saloon at the pumps.
Ownership: Mercedes-AMG C 63 S Saloon vs Porsche 718 Cayman GT4
This is a petrol V8 ownership profile. Hybrid battery warranty and electric-range claims do not apply. Existing price history is retained for the separate pricing review.
Porsche ownership provides a reliable and extensive dealer network, ensuring that the Cayman GT4 is well-supported throughout its life. As a naturally aspirated model, the GT4 has retained significant residual value, making it a sound financial proposition for enthusiasts. Servicing intervals are well-defined, and while specific GT4 components might require longer lead times, the mechanical robustness of the 4.0-litre engine offers peace of mind. It remains a model with a dedicated community and strong factory support, ensuring that this iteration of the Cayman will remain a coveted machine for years to come.
Head-to-head, the division is clear: the Mercedes-AMG C 63 S Saloon — Mercedes-Benz servicing and AMG component support; the Porsche 718 Cayman GT4 — Global parts availability; Porsche mechanical systems offer relative longevity for such performance. Characteristic of the Mercedes-AMG C 63 S Saloon: Confirm service history, tyres and brake specification on the individual car. For the Porsche 718 Cayman GT4: Consistent residual value; popular status ensures liquidity in the pre-owned sports car market. On the wallet the two diverge at £55,000 versus £84,000 — a £29,000 difference.