Audi RS6 Avant vs Porsche 718 Cayman GT4
Compare the Audi RS6 Avant vs Porsche 718 Cayman GT4. The Porsche 718 Cayman GT4 is £30,000 cheaper. The Audi RS6 Avant is 0.8s quicker to 60mph. The Porsche 718 Cayman GT4 is more fuel efficient. Full performance, cost & ownership breakdown.
The Audi RS6 Avant is priced from £108,000, powered by a 4.0L Twin-Turbo V8, producing 591 hp, with 800 Nm of torque, reaching 0-62 mph in 3.6 s, a top speed of 155 mph (standard limiter), sent to the road via all-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 Audi RS6 Avant offers a 565-litre boot, folding rear seats, runs on petrol, returns around 24 mpg, is covered by a 3 years / 60,000 miles (original UK cover; first 2 years unlimited) 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 £30,000 cheaper than its rival, both require around £1,100 per year in maintenance, the Porsche 718 Cayman GT4 is the more fuel-efficient choice, the Audi RS6 Avant has 73 L fuel tank, the Porsche 718 Cayman GT4 has 64 L fuel tank.
Driving Character: Audi RS6 Avant vs Porsche 718 Cayman GT4
The RS6 Avant is the definitive super-estate, wielding a 4.0L twin-turbo V8 that delivers 591 hp with crushing authority. Its Quattro system and all-wheel steering work in tandem to shrink the car’s perceived size, allowing it to navigate complex B-roads with surprising ease. The power delivery is immediate, bolstered by mild-hybrid assistance that masks any hint of lag. It is a master of cross-country velocity, offering a level of grip and composure that remains unmatched in the sector. While the 4575 lbs mass is present, the chassis balance is so well-sorted that it never feels overwhelmed or ponderous.
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 Audi RS6 Avant — 591hp estate car with AWD; fastest family estate in its class; the Porsche 718 Cayman GT4 — 4.0L naturally aspirated flat-six; mid-engine architecture provides exceptional balance during corner entry. Characteristic of the Audi RS6 Avant: Air suspension and adaptive dampers span luxury to performance seamlessly. For the Porsche 718 Cayman GT4: Direct steering response; high-grade chassis hardware encourages precise lines on technical circuits. In outright terms it is 591 hp against 414 — a 177 hp gap — and the Audi RS6 Avant reaches 60 mph 0.8s sooner.
Interior & Cabin: Audi RS6 Avant vs Porsche 718 Cayman GT4
The cabin is a sanctuary of technology and luxury, defined by the high-definition Virtual Cockpit Plus and exquisitely finished Valcona leather. Every surface speaks to Audi's commitment to quality, with supportive sports seats that hold the driver firmly during high-speed cornering. The interior design is sophisticated, blending sharp, angular lines with an understated elegance. Despite being a tech-forward environment, the ergonomics remain intuitive, ensuring that even complex adjustments are simple to perform. It is a space designed for long journeys, offering a sense of calm and control, even when the engine is under full load.
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 Audi RS6 Avant — Premium estate cabin with genuine rear seat space and huge load area; the Porsche 718 Cayman GT4 — Ergonomic control placement; steering wheel diameter and shifter position offer natural driver connection. Characteristic of the Audi RS6 Avant: Optional carbon, Alcantara, and sport seats; widely personalised in practice. For the Porsche 718 Cayman GT4: Alcantara upholstery and brushed aluminium; functional cabin design favours long-term material durability.
Daily Usability: Audi RS6 Avant vs Porsche 718 Cayman GT4
Practically, the RS6 Avant is unrivalled as a high-performance family carrier. With 565 litres of boot space, which expands significantly when the seats are folded, it is ready for almost any task. The air suspension is a revelation, offering a plush, compliant ride for family trips while firming up instantly for spirited driving. Its wide body can be a liability in tight car parks, making the camera system a mandatory tool for urban navigation. However, the sheer ease with which it traverses miles in total comfort makes it an exceptional candidate for a single-car garage.
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 Audi RS6 Avant — 565L boot with rear seats; grows to 1,680L with seats folded — best in class; the Porsche 718 Cayman GT4 — Dual luggage compartments; combined 150L boot and front trunk facilitate extended touring capability. Characteristic of the Audi RS6 Avant: Genuinely usable as family and performance car simultaneously. For the Porsche 718 Cayman GT4: 115 mm ground clearance provides utility; ride quality remains acceptable for occasional spirited driving. that means 565 litres of boot space against 150, plus a usable front boot in the Porsche 718 Cayman GT4, and everyday running costs that favour the Porsche 718 Cayman GT4 at the pumps.
Ownership: Audi RS6 Avant vs Porsche 718 Cayman GT4
Owning an RS6 Avant is an investment in unparalleled capability, though one must account for the significant running costs. With 24 mpg fuel economy and the wear associated with moving such high performance, it is not a cheap car to run. However, the Audi dealer network is top-tier, and the vehicle enjoys strong residual values, with enthusiasts constantly hunting for well-maintained examples. The annual maintenance costs are predictable for the segment, and the car's widespread support ensures longevity. For those who can stomach the fuel and service bills, it offers a level of excellence that is difficult to replicate.
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 Audi RS6 Avant — RS6 is the definitive dual-purpose performance estate; values reflect broad demand; the Porsche 718 Cayman GT4 — Global parts availability; Porsche mechanical systems offer relative longevity for such performance. Characteristic of the Audi RS6 Avant: Audi Approved Used programme strong; wide service support. 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 £108,000 versus £84,000 — a £24,000 difference, and warranty cover of 3 years / 60,000 miles (original UK cover; first 2 years unlimited) versus 3 years / unlimited miles (original UK new-car cover).