Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon
Compare the Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon. The Mercedes-AMG C 63 S Saloon is £30,000 cheaper. The Audi RS6 Avant is 0.4s quicker to 60mph. The Mercedes-AMG C 63 S Saloon 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 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 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 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.
On cost of ownership, the Mercedes-AMG C 63 S Saloon is £30,000 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 Audi RS6 Avant has 73 L fuel tank.
Driving Character: Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon
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 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.
Head-to-head, the division is clear: the Audi RS6 Avant — 591hp estate car with AWD; fastest family estate in its class; the Mercedes-AMG C 63 S Saloon — 4.0-litre twin-turbo V8 and rear-wheel drive. Characteristic of the Audi RS6 Avant: Air suspension and adaptive dampers span luxury to performance seamlessly. For the Mercedes-AMG C 63 S Saloon: Nine-speed MCT gearbox and electronically controlled rear differential. In outright terms it is 591 hp against 503 — a 88 hp gap — and the Audi RS6 Avant reaches 60 mph 0.4s sooner.
Interior & Cabin: Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon
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 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.
Head-to-head, the division is clear: the Audi RS6 Avant — Premium estate cabin with genuine rear seat space and huge load area; the Mercedes-AMG C 63 S Saloon — Four-door W205 cabin with separate central display. Characteristic of the Audi RS6 Avant: Optional carbon, Alcantara, and sport seats; widely personalised in practice. For the Mercedes-AMG C 63 S Saloon: Facelift instrument and steering-wheel controls; equipment varies by car.
Daily Usability: Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon
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.
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.
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 Mercedes-AMG C 63 S Saloon — Five-seat saloon layout and 435-litre boot. Characteristic of the Audi RS6 Avant: Genuinely usable as family and performance car simultaneously. For the Mercedes-AMG C 63 S Saloon: 11.8-metre turning circle in the UK brochure. that means 565 litres of boot space against 435, and everyday running costs that favour the Mercedes-AMG C 63 S Saloon at the pumps.
Ownership: Audi RS6 Avant vs Mercedes-AMG C 63 S Saloon
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.
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.
Head-to-head, the division is clear: the Audi RS6 Avant — RS6 is the definitive dual-purpose performance estate; values reflect broad demand; the Mercedes-AMG C 63 S Saloon — Mercedes-Benz servicing and AMG component support. Characteristic of the Audi RS6 Avant: Audi Approved Used programme strong; wide service support. For the Mercedes-AMG C 63 S Saloon: Confirm service history, tyres and brake specification on the individual car. On the wallet the two diverge at £108,000 versus £55,000 — a £53,000 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).