Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS
Compare the Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS. The Porsche 718 Cayman GT4 RS is £47,000 cheaper. The Mercedes-AMG GT is 0.3s quicker to 60mph. The Porsche 718 Cayman GT4 RS is more fuel efficient. Full performance, cost & ownership breakdown.
The Mercedes-AMG GT is priced from £155,000, powered by a 4.0L Twin-Turbo V8, producing 577 hp, with 800 Nm of torque, reaching 0-60 mph in 3.1s, a top speed of 197 mph, sent to the road via rear-wheel drive. 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 GT offers a 350-litre boot, runs on petrol, returns around 22 mpg, is covered by a 3yr / unlimited mi warranty. 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.
On cost of ownership, the Porsche 718 Cayman GT4 RS is £47,000 cheaper than its rival, the Porsche 718 Cayman GT4 RS costs less in annual maintenance (£1,600 versus £1,300), the Porsche 718 Cayman GT4 RS is the more fuel-efficient choice, a full tank costs around £85 for the Mercedes-AMG GT and £70 for the Porsche 718 Cayman GT4 RS.
Driving Character: Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS
The Mercedes-AMG GT demonstrates the prowess of a front-mid engine layout, prioritising balance and direct feedback for the enthusiast driver. With 577hp directed to the rear wheels via a mechanical limited-slip differential, the car offers a visceral, involving experience. Steering is sharp and communicative, allowing for precise placement in corner apexes, though the rear-wheel-drive platform demands respect in damp conditions. Acceleration is blistering, with a 3.1-second 0-60mph sprint. While less forgiving than its AWD competitors, the AMG GT rewards committed driving with a dynamic repertoire that remains a benchmark for pure driver engagement within the contemporary supercar class.
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.
Head-to-head, the division is clear: the Porsche 718 Cayman GT4 RS takes our 0-100 driving character grading, 82 against 96. Characteristic of the Mercedes-AMG GT: Thunderous AMG V8 with a more usable, GT-focused character than before. For the Porsche 718 Cayman GT4 RS: GT3-derived engine in the lightest, most track-focused Cayman ever. In outright terms it is 577 hp against 493 — a 84 hp gap — and the Mercedes-AMG GT reaches 60 mph 0.3s sooner.
Interior & Cabin: Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS
Inside, the AMG GT presents a cockpit-like environment dominated by a high transmission tunnel and a wide, driver-centric dashboard. The interior materials are of a high standard, showcasing bespoke AMG instruments and Alcantara detailing. Space is deliberately intimate, reflecting the car’s focused nature rather than grand touring comfort. Visibility is somewhat compromised by the low-slung roofline and thick pillars, yet the driving position is perfectly aligned with the pedals and steering wheel. It is an environment designed to insulate the driver from distractions, keeping the focus squarely on the task of piloting a high-performance machine through demanding roads.
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.
Head-to-head, the division is clear: the Mercedes-AMG GT takes our 0-100 interior & cabin grading, 84 against 50. Characteristic of the Mercedes-AMG GT: Genuinely usable 2+2 cabin with strong build quality. For the Porsche 718 Cayman GT4 RS: Stripped-back, motorsport-focused cockpit.
Daily Usability: Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS
Usability in the AMG GT is naturally restricted by its performance-oriented design. The front trunk provides a 260-litre storage area, adequate for light travel but far from comprehensive for extended road trips. The suspension is remarkably firm even in Comfort mode, which can result in an unsettled ride on poor surfaces or urban speed bumps. Ingress and egress require a degree of physical dexterity, given the low ride height and sculpted seats. While the car can manage city errands, its primary habitat remains the open road where its performance credentials can be exercised without the constraints of suburban infrastructure.
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.
Head-to-head, the division is clear: the Mercedes-AMG GT takes our 0-100 daily usability grading, 72 against 35. Characteristic of the Mercedes-AMG GT: More practical than the previous 2-seat GT thanks to rear seats. For the Porsche 718 Cayman GT4 RS: Usable but clearly built for track days over commuting. that means 350 litres of boot space against 125, plus a usable front boot in the Porsche 718 Cayman GT4 RS, and everyday running costs that favour the Porsche 718 Cayman GT4 RS at the pumps.
Ownership: Mercedes-AMG GT vs Porsche 718 Cayman GT4 RS
Owning an AMG GT is an investment in the traditional, high-performance V8 heritage of the brand. Residual values remain strong, bolstered by consistent demand from enthusiasts who prize the V8 character. Servicing is handled through the robust Mercedes dealer network, ensuring that specialists are always within reach, though owners must prepare for high costs associated with performance-grade brakes and tyres. Annual maintenance of £1,600 is standard for the class. Insurance costs reflect the car’s high performance and the complexity of its mechanical components, yet the model remains a prized inclusion in the garages of those who value pure engagement.
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.
Head-to-head, the division is clear: the Porsche 718 Cayman GT4 RS takes our 0-100 ownership grading, 68 against 78. Characteristic of the Mercedes-AMG GT: Backed by Mercedes-AMG's established V8 reliability record. For the Porsche 718 Cayman GT4 RS: Mechanically simple, Porsche-grade reliability. On the wallet the two diverge at £155,000 versus £115,000 — a £40,000 difference, with annual maintenance of £1,600 against £1,300, and warranty cover of 3yr / unlimited mi versus 4yr / 50k mi.