The Vauxhall Signum, particularly the facelifted version introduced in 2005, represents a unique offering from the British automaker. 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 officially sold in the United States, the Signum was a significant model for Vauxhall (and its sister brand Opel) in Europe, competing with vehicles like the Ford Mondeo and Volkswagen Passat. The 2005 facelift brought styling revisions and powertrain updates, including the 3.0 V6 CDTi diesel engine detailed here, aiming to enhance its appeal in a competitive market segment.
The Vauxhall Signum (Facelift 2005)
The Signum, launched in 2003, was based on the Opel/Vauxhall Vectra platform but distinguished itself with a more distinctive fastback profile and a focus on interior space and flexibility. The 2005 facelift refined the exterior styling, updated the interior, and introduced more efficient engine options. The model detailed here, equipped with the 3.0-liter V6 CDTi diesel, was a top-of-the-line offering, providing a balance of performance and fuel economy for European drivers. It was produced from 2005 until 2008, after which the model was discontinued.
Engine & Performance
The heart of this Signum variant is the 3.0-liter V6 CDTi (Common-rail Direct injection Turbocharged Intercooler) diesel engine, designated the Z30DT. This engine produces 184 horsepower at 4000 rpm and a substantial 400 Newton-meters (295.02 lb.-ft.) of torque between 1900 and 2700 rpm. This torque output provides strong acceleration and effortless cruising. The engine features a common rail direct injection system and a turbocharger with intercooler, optimizing combustion and boosting power. The engine’s power-to-liter ratio is 62.2 horsepower per liter. Power is delivered to the front wheels via a six-speed automatic transmission. This configuration allows for a maximum speed of 217 kilometers per hour (134.84 mph). The weight-to-power ratio is 7.7 kg/Hp, and the weight-to-torque ratio is 3.5 kg/Nm, indicating a reasonably efficient powertrain.
Design & Features
The Signum’s body style is a five-door hatchback, offering a practical and versatile layout. Its fastback design contributes to a sleek and modern appearance. The interior is designed with a focus on comfort and space, accommodating five passengers. A key feature of the Signum was its ‘FlexSpace’ seating system, allowing the rear seats to be folded flat or even removed entirely, maximizing cargo capacity. Trunk space ranges from a minimum of 365 liters (12.89 cubic feet) with all seats in place to a maximum of 1410 liters (49.79 cubic feet) with the rear seats folded. Safety features included ABS (Anti-lock Braking System) as standard. The 2005 facelift brought subtle changes to the front and rear styling, including revised headlights and taillights, and updated interior trim materials. The vehicle’s drag coefficient of 0.28 contributes to improved aerodynamic efficiency.
Technical Specifications
| General Information | |
| Brand | Vauxhall |
| Model | Signum |
| Generation | Signum (facelift 2005) |
| Type (Engine) | 3.0 V6 CDTi 24V ECOTEC (184 Hp) Automatic |
| Start of production | 2005 |
| End of production | 2008 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Performance Specs | |
| Fuel consumption (urban) | 11 l/100 km (21.4 US mpg / 25.7 UK mpg / 9.1 km/l) |
| Fuel consumption (extra urban) | 5.8 l/100 km (40.6 US mpg / 48.7 UK mpg / 17.2 km/l) |
| Fuel consumption (combined) | 8 l/100 km (29.4 US mpg / 35.3 UK mpg / 12.5 km/l) |
| CO2 emissions | 216 g/km |
| Fuel Type | Diesel |
| Maximum speed | 217 km/h (134.84 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 7.7 kg/Hp |
| Weight-to-torque ratio | 3.5 kg/Nm |
| Engine Specs | |
| Power | 184 Hp @ 4000 rpm |
| Power per litre | 62.2 Hp/l |
| Torque | 400 Nm @ 1900-2700 rpm (295.02 lb.-ft. @ 1900-2700 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | Z30DT |
| Engine displacement | 2958 cm3 (180.51 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Compression ratio | 18.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 7.25 l (7.66 US qt | 6.38 UK qt) |
| Coolant capacity | 8.3 l (8.77 US qt | 7.3 UK qt) |
| Space, Volume and Weights | |
| Kerb Weight | 1415 kg (3119.54 lbs) |
| Trunk (boot) space – minimum | 365 l (12.89 cu. ft.) |
| Trunk (boot) space – maximum | 1410 l (49.79 cu. ft.) |
| Fuel tank capacity | 60 l (15.85 US gal | 13.2 UK gal) |
| Dimensions | |
| 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) |
| Drag coefficient (Cd) | 0.28 |
| Drivetrain, Brakes and Suspension | |
| Drivetrain Architecture | Internal Combustion engine (ICE) drives the front wheels |
| Drive wheel | Front wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission |
| Front suspension | Independent, type McPherson with coil spring and anti-roll bar |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
