The Audi RS4 Cabriolet (8E, B7) 4.2 FSI V8 32V, produced between 2006 and 2009, represents the open-top variant of Audi’s high-performance RS4 model line. Based on the B7 generation Audi A4 Cabriolet, the RS4 Cabriolet aimed to deliver the exhilarating performance of its coupe sibling in a more visceral, wind-in-your-hair package. It occupied the top echelon of the A4 Cabriolet range, offering a significant performance upgrade over the standard 1.8T and 3.2 V6 models. The RS4 Cabriolet was primarily marketed in Europe and other regions where demand for high-performance convertibles remained strong, though limited numbers were imported to the United States as grey market vehicles.
Technical Specifications
| Brand | Audi |
| Model | RS4 |
| Generation | RS4 Cabrio (8E, B7) |
| Type (Engine) | 4.2 FSI V8 32V (420 Hp) quattro |
| Start of production | 2006 |
| End of production | 2009 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (economy) – urban | 19.9 l/100 km (11.8 US mpg) |
| Fuel consumption (economy) – extra urban | 10.3 l/100 km (22.8 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.9 sec |
| Acceleration 0 – 62 mph | 5.9 sec |
| Acceleration 0 – 60 mph | 5.6 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 4.4 kg/Hp |
| Weight-to-torque ratio | 4.3 kg/Nm |
| Power | 420 Hp @ 7800 rpm |
| Power per litre | 100.9 Hp/l |
| Torque | 430 Nm @ 5500 rpm (317.15 lb.-ft. @ 5500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | BNS |
| Engine displacement | 4163 cm3 (254.04 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 84.5 mm (3.33 in.) |
| Piston Stroke | 92.8 mm (3.65 in.) |
| Compression ratio | 12.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Naturally aspirated engine |
| Engine oil capacity | 9.6 l (10.14 US qt | 8.45 UK qt) |
| Coolant | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1855 kg (4089.57 lbs.) |
| Trunk (boot) space – minimum | 246 l (8.69 cu. ft.) |
| Trunk (boot) space – maximum | 315 l (11.12 cu. ft.) |
| Fuel tank capacity | 63 l (16.64 US gal | 13.86 UK gal) |
| Length | 4573 mm (180.04 in.) |
| Width | 1777 mm (69.96 in.) |
| Height | 1391 mm (54.76 in.) |
| Wheelbase | 2650 mm (104.33 in.) |
| Front track | 1522 mm (59.92 in.) |
| Rear (Back) track | 1518 mm (59.76 in.) |
| Minimum turning circle | 11.1 m (36.42 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears | 6 |
| Gearbox type | Manual transmission |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Independent on trapezoidal lever |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 255/40 R18 |
| Wheel rims size | 18 |
Powertrain & Engine Architecture
The heart of the RS4 Cabriolet is Audi’s naturally aspirated 4.2-liter V8 engine, designated the BNS engine code. This engine is a significant departure from the turbocharged engines commonly found in other A4 variants. It features a 90-degree V-angle, four valves per cylinder, and a high 12.5:1 compression ratio. The engine utilizes Audi’s FSI (Fuel Stratified Injection) direct injection technology, which precisely meters fuel directly into the combustion chamber, improving efficiency and power output. The valvetrain employs variable valve timing on both intake and exhaust camshafts, further optimizing performance across the rev range. The engine produces 420 horsepower at 7800 rpm and 317 lb-ft of torque at 5500 rpm. Power is delivered to all four wheels via Audi’s quattro all-wheel-drive system and a standard six-speed manual transmission. An optional automatic transmission was not offered for this generation RS4.
Driving Characteristics
The RS4 Cabriolet delivers a thrilling driving experience characterized by its responsive engine, precise handling, and confident grip. The naturally aspirated V8 provides a linear power delivery, building smoothly to its 7800 rpm redline. The six-speed manual transmission offers precise shifts, allowing the driver to fully exploit the engine’s power. Compared to the standard A4 Cabriolet models, the RS4 exhibits significantly improved acceleration and braking performance. While the manual transmission provides a more engaging experience, the added weight of the convertible top and reinforced chassis compared to the coupe results in a slightly slower 0-60 mph time of around 5.6 seconds. The quattro all-wheel-drive system provides excellent traction in all weather conditions, enhancing stability and control.
Equipment & Trim Levels
The RS4 Cabriolet came generously equipped as standard. Interior features included sport seats upholstered in Nappa leather with embossed RS4 logos, a three-spoke sport steering wheel, and carbon fiber trim accents. Standard exterior features included a unique RS4 body kit with aggressive front and rear bumpers, side skirts, and a rear spoiler. Larger brakes with ventilated discs were also standard. Optional extras included a premium sound system, navigation system, and various customization options for interior trim and exterior paint colors. The overall interior ambiance was focused on a sporty and luxurious feel, befitting the RS4’s high-performance status.
Chassis & Braking
The RS4 Cabriolet features a reinforced chassis compared to the standard A4 Cabriolet to enhance rigidity and handling. The suspension is lowered and stiffened, with upgraded shock absorbers and stabilizer bars. The front suspension utilizes a multi-link design, while the rear suspension employs a trapezoidal link setup. Braking duties are handled by large, ventilated disc brakes on all four wheels, providing ample stopping power. The ABS (Anti-lock Braking System) is standard, enhancing safety and control during hard braking. The RS4 also featured a speed-sensitive steering system, providing increased assistance at low speeds and a more direct feel at higher speeds.
Market Reception & Comparison
The RS4 Cabriolet was generally well-received by automotive critics, who praised its exhilarating performance, precise handling, and luxurious interior. However, some critics noted the added weight of the convertible top compromised the car’s handling slightly compared to the coupe. Compared to the standard A4 Cabriolet models, the RS4 offered a substantial performance upgrade, but at a significant price premium. Within the RS4 lineup, the Cabriolet was positioned as the more exclusive and emotionally driven option, appealing to drivers who prioritized open-air driving enjoyment over ultimate track performance. Fuel economy was predictably poor, reflecting the high-performance nature of the engine.
Legacy
The Audi RS4 Cabriolet (8E, B7) remains a desirable and collectible vehicle today. The 4.2-liter V8 engine is known for its reliability, provided it receives regular maintenance. However, like any high-performance vehicle, the RS4 can be expensive to maintain, with potential issues including oil leaks, timing chain wear, and carbon buildup on the intake valves. The quattro all-wheel-drive system is generally robust, but requires periodic servicing. On the used car market, RS4 Cabriolets command a premium price, reflecting their rarity, performance, and enthusiast appeal. The B7 RS4 represents a high point in Audi’s performance heritage, offering a unique blend of luxury, performance, and open-air driving enjoyment.








