Opel Signum 1.9 CDTI (150 Hp) Automatic

The Opel Signum 1.9 CDTI Automatic: A Unique European Proposition

The Opel Signum, a distinctive executive-class large hatchback, represented an ambitious effort by the German automaker Opel (then part of General Motors Europe) to carve out a new niche in the competitive European market. Launched in 2003 and based on the extended platform of the Opel Vectra C, the Signum aimed to blend the spaciousness and practicality of a station wagon with the refined comfort and appointments of a premium sedan. This detailed analysis focuses on the Opel Signum 1.9 CDTI (150 Hp) Automatic variant, a popular diesel powertrain option available during its brief production run from May 2004 to 2005. Designed primarily for European consumers, particularly business users and families seeking exceptional versatility and comfort, the Signum was never officially sold in the United States, making it a fascinating example of European automotive engineering and market strategy.

The Signum’s concept was somewhat ahead of its time, proposing a vehicle that offered more interior flexibility than traditional sedans without committing to the full utility vehicle aesthetic of an MPV or SUV. It was positioned above the conventional Vectra hatchback, targeting customers who might otherwise consider vehicles like the Volkswagen Passat Variant (wagon) or even entry-level premium offerings. The 1.9 CDTI engine, a robust and efficient diesel, coupled with an automatic transmission, underscored its appeal as a comfortable and economical long-distance cruiser, perfectly suited to the demands of European highways.

Engine and Performance

Powering the Opel Signum 1.9 CDTI Automatic is a sophisticated 1.9-liter (1910 cm³ or 116.56 cu. in.) inline four-cylinder diesel engine, designated with the code Z19DTH. This engine, a product of a joint venture between General Motors and Fiat Powertrain Technologies (FPT), was a highly regarded unit in its era, known for its strong performance and excellent fuel economy. Utilizing a common rail direct fuel injection system, turbocharger, and intercooler, it delivered a healthy 150 horsepower at 4000 rpm. More impressively for a diesel, it produced a substantial 236.02 lb-ft (320 Nm) of torque at a low 2000 rpm, providing strong pulling power and effortless acceleration, particularly beneficial for highway overtaking and carrying heavy loads.

The engine’s architecture features a double overhead camshaft (DOHC) valvetrain with four valves per cylinder, contributing to efficient combustion and power delivery. With a compression ratio of 17.5:1, it was optimized for diesel fuel efficiency. The power-to-weight ratio for this variant stands at 95.8 Hp per tonne (10.4 kg/Hp), while the torque-to-weight ratio is 204.5 Nm per tonne (4.9 kg/Nm), indicating a well-balanced powertrain for its size and intended use.

Mated to this potent diesel engine was a smooth-shifting 6-speed automatic transmission. This gearbox was engineered to provide a comfortable and refined driving experience, minimizing driver fatigue on long journeys while efficiently managing the engine’s torque output. Performance figures for the Opel Signum 1.9 CDTI (150 Hp) Automatic reflect its competent nature: it could accelerate from 0 to 60 mph in 10.2 seconds (0-100 km/h in 10.7 seconds) and reach a maximum speed of 127.38 mph (205 km/h).

Fuel efficiency was a key selling point for this diesel model. The Signum 1.9 CDTI Automatic achieved an impressive 24 US mpg (9.8 l/100 km) in urban driving conditions and an even better 41.3 US mpg (5.7 l/100 km) on the extra-urban cycle. These figures were highly competitive for a vehicle of its size and class in the mid-2000s, offering significant cost savings for high-mileage drivers in Europe where diesel fuel was prevalent and often taxed favorably.

Design and Features

The Opel Signum’s design was truly distinctive, diverging from the traditional hatchback or sedan formula. Classified as a 5-door hatchback, its extended wheelbase (111.42 inches or 2830 mm) – shared with the long-wheelbase Vectra Caravan (wagon) – allowed for exceptional rear passenger space, a primary focus of its design. The overall length was 182.52 inches (4636 mm), width 70.79 inches (1798 mm), and height 57.48 inches (1460 mm). Its profile featured a somewhat elongated, coupe-like roofline that gently sloped towards a practical tailgate, providing good access to the cargo area. The drag coefficient (Cd) of 0.33 was respectable for its class, contributing to its highway efficiency and reduced wind noise.

The interior of the Signum was where its innovative “FlexSpace” concept truly shone. Unlike a conventional sedan, the rear cabin offered two individual full-size seats, which could slide forwards and backwards by 5.1 inches (130 mm), recline, and even fold flat independently. A third, narrower central seat could also be folded down to reveal a multi-functional storage and armrest unit, complete with cupholders and even an optional integrated refrigerator. This level of flexibility was unparalleled in its segment and aimed to provide a first-class experience for rear passengers, making it ideal for executive transport or family road trips.

Standard features for a vehicle of its era included hydraulic power steering (rack and pinion type), front-wheel drive, and a robust suspension setup featuring coil springs at both the front and rear. Braking was handled by ventilated discs at the front and solid discs at the rear, complemented by an Anti-lock Braking System (ABS) for enhanced safety. The car rode on 215/55 R16 tires mounted on 6.5J x 16-inch wheel rims, providing a comfortable and stable ride.

The cargo capacity was also impressive for its unique body style. With the rear seats in their standard position, the trunk offered 12.89 cu. ft. (365 liters) of space. When the rear seats were folded down, this expanded significantly to 49.79 cu. ft. (1410 liters), rivaling many traditional station wagons. This adaptability underscored the Signum’s commitment to practicality and versatility.

Technical Specifications

Legacy and Market Impact

The Opel Signum, particularly the 1.9 CDTI Automatic variant, holds a unique place in Opel’s history. It was a bold attempt to create a new market segment, focusing on executive comfort and unparalleled interior flexibility for its class. Despite its innovative design and practical advantages, the Signum struggled to achieve widespread commercial success. Its unconventional styling and niche positioning meant that many buyers were unsure where to place it within the established automotive hierarchy. It wasn’t quite a traditional sedan, nor a full-fledged station wagon, and its premium aspirations often put it in contention with more established and brand-conscious luxury marques.

In its primary European market, the Signum faced stiff competition from a diverse array of vehicles. Mainstream competitors included the highly popular Ford Mondeo, Volkswagen Passat, Renault Laguna, and Peugeot 407, all of which offered more conventional body styles and often more aggressive pricing. On the premium end, buyers might have opted for a BMW 3 Series Touring or Audi A4 Avant, which, while potentially less flexible in terms of seating, carried a stronger brand prestige. The Signum’s strong points, such as its comfortable ride, refined diesel engine, and particularly its versatile “FlexSpace” interior, were highly praised by those who understood its unique proposition. However, this praise often didn’t translate into the significant sales volumes Opel had hoped for.

The 1.9 CDTI engine itself, however, proved to be a reliable and popular choice across various GM Europe models, including the Vectra and Astra, cementing its reputation as a workhorse diesel. The Signum’s short production run for this specific variant (2004-2005) highlights the rapid evolution of automotive design and consumer preferences during that period. Ultimately, the Signum was discontinued in 2008, with Opel shifting its focus towards more conventional, yet equally stylish and technologically advanced, models like the Insignia, which effectively consolidated the roles of both the Vectra and Signum.

Despite its limited market impact, the Opel Signum remains an interesting case study in automotive innovation. It showcased Opel’s willingness to experiment with packaging and interior design, demonstrating a forward-thinking approach to passenger comfort and versatility. While it may not have been a sales blockbuster, its legacy lies in its contribution to the ongoing quest for adaptable and user-centric vehicle interiors, influencing subsequent designs that prioritize modularity and space utilization. For those in Europe seeking a comfortable, efficient, and uniquely practical executive car, the Signum 1.9 CDTI Automatic offered a compelling, if unconventional, choice.