Audi RS5 Sportback vs Porsche 718 Cayman GT4
Compare the Audi RS5 Sportback vs Porsche 718 Cayman GT4. The Audi RS5 Sportback is £13,000 cheaper. The Audi RS5 Sportback is 0.3s quicker to 60mph. The Audi RS5 Sportback is more fuel efficient. Full performance, cost & ownership breakdown.
The Audi RS5 Sportback is priced from £65,000, powered by a 2.9L Twin-Turbo V6, producing 444 hp, with 600 Nm of torque, reaching 0-60 mph in 3.9s, a top speed of 174 mph, 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 0-60 mph in 4.2s, a top speed of 188 mph, sent to the road via rear-wheel drive.
The Audi RS5 Sportback offers a 480-litre boot, folding rear seats, runs on petrol, returns around 30 mpg, is covered by a 3yr / unlimited mi 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 4yr / 50k mi warranty.
On cost of ownership, the Audi RS5 Sportback is £13,000 cheaper than its rival, the Audi RS5 Sportback costs less in annual maintenance (£1,000 versus £1,100), the Audi RS5 Sportback is the more fuel-efficient choice, a full tank costs around £80 for the Audi RS5 Sportback and £70 for the Porsche 718 Cayman GT4.
Driving Character: Audi RS5 Sportback vs Porsche 718 Cayman GT4
The RS5 Sportback delivers a sophisticated driving experience focused on immense, all-weather pace. Its 2.9L twin-turbo V6 pushes 444 hp, providing a linear and authoritative surge of acceleration that makes the 0-60 sprint feel effortless. The Quattro system, paired with a sport differential, ensures the chassis feels planted and neutral, even in challenging conditions. While it may lack the raw, emotive bark of a V8, the technical precision is hard to ignore. It is a car that covers ground with clinical efficiency, keeping the driver composed and confident regardless of the severity of the road surface.
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 Porsche 718 Cayman GT4 takes our 0-100 driving character grading, 72 against 93. Characteristic of the Audi RS5 Sportback: Composed, quattro-assured pace with a characterful twin-turbo V6. For the Porsche 718 Cayman GT4: Purist mid-engined chassis balance and involvement. In outright terms it is 444 hp against 414 — a 30 hp gap — and the Audi RS5 Sportback reaches 60 mph 0.3s sooner.
Interior & Cabin: Audi RS5 Sportback vs Porsche 718 Cayman GT4
The cabin is a triumph of function and premium finish, centring on the high-resolution Virtual Cockpit. Everything is exactly where a driver would expect it, with high-quality materials and a robust build feel that characterises Audi’s best interiors. The Sportback silhouette does slightly compromise headroom for rear passengers, though the four-door configuration makes it far more accessible than a traditional coupe. It feels intimate yet spacious, balancing a cockpit-style atmosphere with sufficient room for adults. While it shares some architecture with the standard A5, the RS-specific trim and seating elevate the experience to something truly special.
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 RS5 Sportback takes our 0-100 interior & cabin grading, 82 against 55. Characteristic of the Audi RS5 Sportback: Spacious, well-finished cabin with practical 5-door hatch access. For the Porsche 718 Cayman GT4: Motorsport-flavoured cabin with genuine everyday livability.
Daily Usability: Audi RS5 Sportback vs Porsche 718 Cayman GT4
Practicality is the RS5 Sportback’s hidden talent, blending high performance with genuine usability. The 480L boot is surprisingly cavernous, and the rear doors make loading children or shopping a non-issue. Its footprint is manageable for urban environments, allowing for relatively stress-free parking. The ride, while undeniably firm when set to Dynamic, remains supple in Comfort, smoothing out motorway undulations effectively. It is a car that thrives on long-distance grand touring, where its stability and power come into their own, yet it remains perfectly at home running mundane errands through a congested city centre.
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 RS5 Sportback takes our 0-100 daily usability grading, 85 against 68. Characteristic of the Audi RS5 Sportback: Genuinely practical everyday performance car with a usable boot. For the Porsche 718 Cayman GT4: Surprisingly civil ride and quiet cabin for a track-focused car. that means 480 litres of boot space against 150, plus a usable front boot in the Porsche 718 Cayman GT4, and everyday running costs that favour the Audi RS5 Sportback at the pumps.
Ownership: Audi RS5 Sportback vs Porsche 718 Cayman GT4
Ownership costs for the RS5 Sportback are balanced, leaning towards the premium end of the mid-size performance spectrum. Achieving 30 mpg on a steady run is a welcome benefit of the V6 layout, though enthusiastic driving will see that figure plummet. Servicing intervals are well-structured, though the Quattro driveline does require specific attention to remain in peak condition. Audi’s expansive dealer network is a massive advantage, ensuring that parts and expertise are never far away. Strong residuals and a broad appeal make this a sound financial proposition for a high-performance vehicle, provided you are prepared for the annual maintenance budget.
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 RS5 Sportback takes our 0-100 ownership grading, 78 against 78. Characteristic of the Audi RS5 Sportback: Strong Audi reliability reputation. For the Porsche 718 Cayman GT4: Mechanically simple, Porsche-grade reliability. On the wallet the two diverge at £65,000 versus £84,000 — a £19,000 difference, with annual maintenance of £1,000 against £1,100, and warranty cover of 3yr / unlimited mi versus 4yr / 50k mi.