The Vauxhall Signum, particularly the facelifted version introduced in 2005, represents an intriguing chapter in the history of British automotive design. Positioned as a hatchback – often described as a ‘sports hatch’ – it aimed to blend the practicality of a family car with a more dynamic driving experience. While never a major sales success in the United Kingdom, the Signum was a key model for Vauxhall (and its sister brand Opel in mainland Europe) in the mid-2000s, offering a distinctive alternative to more conventional estate cars and sedans. This article focuses on the 2.8 Turbo V6 variant, a performance-oriented version of the Signum available between 2005 and 2008.
The Vauxhall Signum: A Unique Offering
The Signum was based on the Opel/Vauxhall Vectra platform, but distinguished itself through its unique fastback styling and a focus on interior space and flexibility. The “facelift” of 2005 brought revised front and rear styling, along with interior upgrades, aiming to modernize the vehicle and enhance its appeal. The 2.8 Turbo V6 model was the flagship of the range, offering significantly more power and performance than the more common four-cylinder engines. It was designed to appeal to drivers seeking a comfortable yet engaging driving experience, with a focus on grand touring rather than outright sportiness.
Engine & Performance
The heart of the Signum 2.8 Turbo V6 is its 2792 cc (170.38 cu. in.) V6 engine, designated Z28NET. This engine produces 250 horsepower (Hp) at 5500 rpm and 350 Newton-meters (258.15 lb.-ft.) of torque between 1800 and 4500 rpm. The use of a turbocharger and intercooler significantly boosts power output, providing strong acceleration and effortless cruising. Power per liter is an impressive 89.5 Hp/l. This power is delivered to the front wheels via a six-speed automatic transmission. The Signum 2.8 Turbo V6 has an electronically limited top speed of 250 km/h (155.34 mph). The weight-to-power ratio of 6.7 kg/Hp and weight-to-torque ratio of 4.8 kg/Nm contribute to a responsive driving experience. While not a lightweight vehicle at 1675 kg (3692.74 lbs.), the engine’s torque output helps to overcome this, providing brisk performance in real-world driving conditions.
Design & Features
The Signum’s body style is a five-door hatchback, offering a practical and versatile cargo area. The fastback design gives it a sleek and modern appearance, differentiating it from more traditional hatchbacks. Inside, the Signum prioritizes comfort and space, with seating for four passengers. The interior features were upgraded during the 2005 facelift, with improved materials and a more contemporary dashboard design. Standard features included air conditioning, power windows, and a CD stereo system. Safety features, crucial for a vehicle of this era, included ABS (Anti-lock Braking System) and front and rear disc brakes. The Signum’s suspension – independent McPherson struts at the front and a torsion beam at the rear – is tuned for a balance between comfort and handling. The vehicle rides on 235/40 R18 tires, contributing to its road grip and stability.
Technical Specifications
| Brand | Vauxhall |
| Model | Signum |
| Generation | Signum (facelift 2005) |
| Type (Engine) | 2.8 Turbo V6 (250 Hp) Automatic |
| Start of production | 2005 |
| End of production | 2008 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 4 |
| Doors | 5 |
| Fuel consumption (urban) | 17.4 l/100 km (13.5 US mpg / 16.2 UK mpg / 5.7 km/l) |
| Fuel consumption (extra urban) | 7.6 l/100 km (30.9 US mpg / 37.2 UK mpg / 13.2 km/l) |
| Fuel consumption (combined) | 11.2 l/100 km (21 US mpg / 25.2 UK mpg / 8.9 km/l) |
| CO2 emissions | 269 g/km |
| Fuel Type | Petrol (Gasoline) |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 6.7 kg/Hp |
| Weight-to-torque ratio | 4.8 kg/Nm |
| Power | 250 Hp @ 5500 rpm |
| Power per litre | 89.5 Hp/l |
| Torque | 350 Nm @ 1800-4500 rpm (258.15 lb.-ft. @ 1800-4500 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | Z28NET |
| Engine displacement | 2792 cm3 (170.38 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 89 mm (3.5 in.) |
| Piston Stroke | 74.8 mm (2.94 in.) |
| Compression ratio | 9.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 6 l (6.34 US qt | 5.28 UK qt) |
| Coolant | 7.5 l (7.93 US qt | 6.6 UK qt) |
| Kerb Weight | 1675 kg (3692.74 lbs.) |
| Fuel tank capacity | 60 l (15.85 US gal | 13.2 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Length | 4651 mm (183.11 in.) |
| Width | 1798 mm (70.79 in.) |
| Width including mirrors | 2036 mm (80.16 in.) |
| Height | 1466 mm (57.72 in.) |
| Wheelbase | 2830 mm (111.42 in.) |
| Minimum turning circle | 11.92 m (39.11 ft.) |
| Drivetrain Architecture | ICE, Front wheel drive |
| Drive wheel | Front wheel drive |
| Number of gears | 6 |
| Gearbox type | Automatic transmission |
| Front suspension | Independent, McPherson with coil spring and anti-roll bar |
| Rear suspension | Torsion |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic |
| Tires size | 235/40 R18 |
The Vauxhall Signum 2.8 Turbo V6, while not a mainstream success, remains a distinctive and interesting vehicle. It offered a compelling blend of practicality, comfort, and performance, appealing to those seeking an alternative to more conventional family cars. Its unique styling and powerful engine continue to attract enthusiasts today.
