Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63
Compare the Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63. The Mercedes-AMG C 63 is £30,000 cheaper. The Porsche 718 Cayman GT4 RS is 0.4s quicker to 60mph. The Mercedes-AMG C 63 is more fuel efficient. Full performance, cost & ownership breakdown.
The Porsche 718 Cayman GT4 RS is priced from £115,000, powered by a 4.0L Flat-6, producing 493 hp, with 450 Nm of torque, reaching 0-60 mph in 3.4s, a top speed of 196 mph, sent to the road via rear-wheel drive. The Mercedes-AMG C 63 is priced from £55,000, powered by a 4.0L Twin-Turbo V8, producing 503 hp, with 700 Nm of torque, reaching 0-60 mph in 3.8s, a top speed of 180 mph, sent to the road via rear-wheel drive.
The Porsche 718 Cayman GT4 RS offers a 125-litre boot, a usable front boot, runs on petrol, returns around 23 mpg, is covered by a 4yr / 50k mi warranty. The Mercedes-AMG C 63 offers a 455-litre boot, folding rear seats, runs on petrol, returns around 26 mpg, is covered by a 3yr / unlimited mi warranty.
On cost of ownership, the Mercedes-AMG C 63 is £30,000 cheaper than its rival, the Mercedes-AMG C 63 costs less in annual maintenance (£1,300 versus £1,100), the Mercedes-AMG C 63 is the more fuel-efficient choice, a full tank costs around £70 for the Porsche 718 Cayman GT4 RS and £80 for the Mercedes-AMG C 63.
Driving Character: Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63
The Porsche 718 Cayman GT4 RS represents the apex of the 718 platform, transplanting a 493hp naturally aspirated flat-six from the GT3 into a mid-engine chassis. The result is a machine with staggering agility and a turn-in response that makes even the standard GT4 feel soft. The chassis balance is dominated by rear-end grip and sharp, responsive steering that provides constant feedback. It is an extreme instrument, demanding a high level of expertise to truly extract its full potential. The power delivery is frenetic, culminating in a high-revving wail that defines the car's racing-inspired character.
The Mercedes-AMG C 63 remains a titan of the executive performance segment, defined by its thunderous 4.0L twin-turbo V8. The engine delivers a character that is increasingly rare, offering an aggressive, theatrical soundscape that is amplified by the mechanical limited-slip differential. The rear-wheel-drive platform provides a traditional, tail-happy balance that rewards a skilled driver, though the sheer power output requires significant caution in adverse weather conditions. It is a car that thrives on the open road, where the balance of torque and power delivery can be fully exploited, making it a visceral, highly engaging piece of German engineering.
Head-to-head, the division is clear: the Porsche 718 Cayman GT4 RS takes our 0-100 driving character grading, 96 against 84. Characteristic of the Porsche 718 Cayman GT4 RS: GT3-derived engine in the lightest, most track-focused Cayman ever. For the Mercedes-AMG C 63: Thunderous twin-turbo V8 with a playful, adjustable rear-drive character. In outright terms it is 493 hp against 503 — a 10 hp gap — and the Porsche 718 Cayman GT4 RS reaches 60 mph 0.4s sooner.
Interior & Cabin: Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63
The interior is a study in weight reduction, featuring CFRP door panels, lightweight door pulls, and carbon bucket seats that lock the driver in place. The presence of the standard roll bar behind the seats signals its intent, creating a sparse, motorsport-focused atmosphere. Sound deadening is intentionally minimal, allowing the mechanical symphony—and the roar of the intake located just behind the driver's head—to flood the cabin. It is not designed for luxury or comfort, but rather as an extension of the driving experience, prioritising tactical feedback and material efficiency above all else.
Inside, the C 63 is a blend of high-end executive luxury and focused performance. The cabin features premium Nappa leather and DINAMICA materials, with AMG-specific detailing that differentiates it from the standard C-Class. The Performance seats provide excellent support during spirited driving while remaining comfortable for daily commuting. Infotainment is delivered through a high-resolution interface that is ergonomic and well-integrated. While the rear seats offer adequate space for adults, the overall interior environment feels sophisticated, maintaining a luxurious ambience that balances the car's extreme performance capabilities with the comfort expected of a premium Mercedes saloon.
Head-to-head, the division is clear: the Mercedes-AMG C 63 takes our 0-100 interior & cabin grading, 50 against 76. Characteristic of the Porsche 718 Cayman GT4 RS: Stripped-back, motorsport-focused cockpit. For the Mercedes-AMG C 63: Flamboyant, premium-feeling cabin with supportive seats.
Daily Usability: Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63
Daily utility is significantly compromised by the track-oriented nature of the GT4 RS. The suspension is exceptionally firm, making it punishing on all but the smoothest road surfaces, and the lack of sound insulation makes it unsuitable for long, tedious commutes. Despite this, the front and rear trunks remain available for storage, and the inclusion of a front-axle lift system helps navigate urban obstacles. While it is technically possible to drive to the track, the RS experience is best reserved for spirited road use or dedicated circuit days rather than routine errands.
Practicality is a cornerstone of the C 63's appeal, offering a 455-litre boot that handles everyday chores with ease. In Comfort mode, the suspension softens significantly, turning the car into a compliant cruiser capable of managing motorway miles without fatigue. It is a vehicle that transitions effortlessly from a daily office commuter to a weekend sports machine. The only real trade-off for this usability is the fuel consumption, which is significant under load, and the wide wheel arches and stance that can make navigating tight city streets or multi-storey car parks an exercise in careful spatial awareness.
Head-to-head, the division is clear: the Mercedes-AMG C 63 takes our 0-100 daily usability grading, 35 against 70. Characteristic of the Porsche 718 Cayman GT4 RS: Usable but clearly built for track days over commuting. For the Mercedes-AMG C 63: Comfortable, well-isolated cruiser despite its firm setup. that means 125 litres of boot space against 455, plus a usable front boot in the Porsche 718 Cayman GT4 RS, and everyday running costs that favour the Mercedes-AMG C 63 at the pumps.
Ownership: Porsche 718 Cayman GT4 RS vs Mercedes-AMG C 63
Owning a 718 Cayman GT4 RS is a high-stakes proposition, with high purchase prices and significant service costs reflecting its status as a low-volume, specialised performance vehicle. Values have appreciated rapidly, as the model occupies a unique space in the modern Porsche lineup. Owners benefit from the comprehensive Porsche Motorsport support network, which is essential for managing RS-specific components that are more expensive and harder to source than standard parts. It is a collector's dream, provided the owner acknowledges the substantial overheads and the demanding nature of maintaining a high-performance track machine.
Owning a C 63 is a relatively straightforward experience, thanks to the vast global Mercedes dealer network and the availability of specialist support. Maintenance is predictably expensive, with high-performance components like tyres and brakes requiring frequent attention, but the overall reliability of the powertrain is well-regarded among the community. As the industry moves toward electrification, the W205 C 63's naturally aspirated-feel V8 is increasingly seen as a desirable classic, helping to stabilise residual values. It remains a benchmark for the segment, offering a combination of daily utility and performance that continues to attract a strong, loyal owner base.
Head-to-head, the division is clear: the Porsche 718 Cayman GT4 RS takes our 0-100 ownership grading, 78 against 66. Characteristic of the Porsche 718 Cayman GT4 RS: Mechanically simple, Porsche-grade reliability. For the Mercedes-AMG C 63: Feels robustly screwed together. On the wallet the two diverge at £115,000 versus £55,000 — a £60,000 difference, with annual maintenance of £1,300 against £1,100, and warranty cover of 4yr / 50k mi versus 3yr / unlimited mi.