The Tipo Quattro (Type Four) program was launched in the late 1970s as a joint venture to develop a family of executive-class sedans efficiently. Fiat (including its Lancia and soon-to-be-acquired Alfa Romeo brands) teamed with Sweden’s Saab to share development costs on a new top-range platform. The aim was to create a common chassis (floorpan, doors, roof, etc.) that all four cars could use, while each company designed its own body, styling, and engines. By 1981 Saab’s collaboration was solidified (Saab had already been building rebadged Autobianchi models for Italy), and Fiat’s engineers had the basic Type Four chassis ready. The platform was finalized by the mid-1980s, and four distinct sedans emerged: the Saab 9000, Fiat Croma, Lancia Thema, and Alfa Romeo 164.
Platform Sharing and Technical Collaboration
All Type Four models shared a 2.67 m wheelbase and basic transverse front-engine, front-wheel-drive architecture. In practice, the Fiat Croma and Saab 9000 were launched as five-door hatchbacks, while the Lancia Thema and Alfa 164 were four-door saloons. Later, Lancia added the only station-wagon variant (designed by Pininfarina) in 1986 and Saab introduced a sedan version (CD) in 1988. To save costs, many parts were interchangeable across brands – for example, the Croma and 9000 use the same windshield, and door handles and mirrors are often shared.
However, each manufacturer stamped its identity on the car. Saab heavily reinforced its 9000 for safety (adding roughly 200 kg) and retained its signature cabin details (such as ignition-on-column instead of on the console). The Saab also uniquely used a solid rear (beam) axle instead of the independent rear suspension fitted to the Italian models. Alfa Romeo’s 164, being last to market, got exclusive suspension geometry and a more aggressive, wedge-shaped body. Lancia styled the Thema in-house (later subcontracting the wagon to Pininfarina), emphasizing comfort and luxury. In sum, all four cars rode on the same Type Four “modular” chassis, but differed in styling, trim, and tuning.
Fiat Croma (1985–1996)
The Fiat Croma (Type 154) was Fiat’s entry on the Tipo Quattro platform. Styled by Giugiaro’s Italdesign, it appeared in late 1985 as a large five-door fastback. It effectively replaced Fiat’s aging Argenta sedan, and was notable as Fiat’s first large car with a transverse engine and front-wheel drive. The original Croma offered 1.6 L and 2.0 L four-cylinder petrol engines (including a 2.0 L turbo and a fuel-saving 2.0 L “CHT” model), plus a 2.5 L Alfa Romeo V6 in some markets. In 1988 Fiat introduced the first passenger diesel with direct injection – a 1.9 L turbo-diesel by Sofim – followed by larger 2.4 L and 2.5 L turbodiesels. The Croma received minor facelifts in 1988 and 1991 to freshen its looks.
Sales were modest, and Fiat ended Croma production in December 1996, exiting the large-family-car market (later re-entering with an unrelated crossover using the Croma name in 2005).
Unique features: The Croma was well appointed for its class, and introduced innovations like multi-point fuel injection and – notably – the world’s first application of a diesel common-rail direct-injection engine in a passenger car (Turbo D i.d.). It was designed to be practical (spacious liftback) rather than sporty.
Saab 9000 (1984–1998)
The Saab 9000 was the Swedish luxury version of the Type Four concept. Debuting in 1984, it was initially a 5‑door hatchback (the 9000 CC Turbo 16) and later offered as a 4‑door notchback (9000 CD) and facelifted hatch (9000 CS). Saab’s approach emphasized safety, aerodynamics (Cd≈0.34) and performance. In fact, the 9000 won “Best Prestige Car 1985” in France (despite early chassis-torsion issues that Saab quickly reinforced). Unlike the Italians, Saab only offered petrol engines: the lineup included 2.0 L four-cylinders (8-valve and 16-valve, naturally aspirated and turbocharged) and later 2.3 L 16-valve fours (naturally aspirated and turbocharged), plus a 3.0 L V6 (GM/Opel-sourced) added in the early 1990s. Notable variants were the high-performance 9000 CS Aero models; for example, the Aero Coupe (hatch) introduced in 1993 used a 2.3 L turbo tuned to 225 PS. Over its production run (1984–1998), Saab built roughly half a million 9000s worldwide. In 1998 the 9000 was replaced by the Saab 9-5 (built on a GM platform), and the Type Four era concluded.
Unique features: The 9000 was Volvo-like in its solidity and safety focus. Its ignition switch remained on the steering column (a Saab trademark). Early 9000s lacked the independent rear suspension of its Italian siblings, using a robust beam axle for extra durability under load. The 9000’s interior and chassis were also reinforced over time to improve rigidity and crash performance. Its performance-oriented Aero models and wide turbo range became hallmarks of Saab engineering.
Lancia Thema (1984–1994)
The Lancia Thema was Lancia’s Type Four luxury sedan. It premiered in late 1984 and was built at Mirafiori (Turin). Stylistically it was more restrained than Saab’s or Alfa’s designs. Initially offered only as a four-door saloon, Lancia later added a Pininfarina-designed station wagon in 1986. The Thema’s engine range was broad: two 2.0 L Fiat/Tritec I4s (a naturally aspirated 8-valve and an intercooled turbo 8-valve), a 2.8 L PRV V6 (tuned to about 150 PS), a 3.0 L Alfa-Romeo V6, and 2.4 L Sofim turbodiesel four-cylinders. The most exotic variant was the Thema 8·32 (introduced in 1986) – a top-of-the-line model powered by a 2.9 L Ferrari-derived V8 (Tipo F105L, 8×3.2 valves) giving around 216 PS. In total, over 336,000 Themas were built by 1994. The Thema earned praise for its comfort and refinement. Production ended in 1994 (Lancia also withdrew from right-hand-drive markets), and it was succeeded by the Lancia Kappa on a new platform.
Unique features: Lancia emphasized luxury and exclusivity. Aside from the Ferrari-V8 8·32 model, the Thema had high-end appointments (leather, wood trim) typical of executive sedans. The Pininfarina station wagon had a sleek, family-friendly design; 21,074 wagons were built. The Thema was Lancia’s flagship and was often noted for its quiet, well-appointed cabin and smooth engines. The 8·32 remains famous as one of the few four-door Ferraris ever made (unique cross-plane crank V8 adapted for saloon use).
Alfa Romeo 164 (1987–1998)
The Alfa Romeo 164 was the sporty Italian upmarket sedan of the group. Introduced in 1987 and styled by Pininfarina (Enrico Fumia), it had a very distinctive design – crisply angular and with a sharply raked tail – unlike the other three Type Four cars. Built in Arese (Milan), it was Alfa’s technological showcase: the 164 was Alfa’s first extensively CAD-designed car and the first to use galvanised steel panels. Sharing the Tipo Quattro underbody, it featured unique double-wishbone front suspension geometry and a fully independent setup for sportier handling.
The 164 was offered only as a four-door saloon. It launched with a range of engines: a 2.0 L Twin Spark 8-valve I4, a 2.0 L turbocharged four-cylinder (marketed only in Italy), and 3.0 L V6s (both 12-valve and a later 24-valve version), plus a 2.5 L VM turbodiesel. In 1990 Alfa introduced the high-performance Quadrifoglio Verde (QV) versions (badged “S” or “QV”) with the most powerful 3.0 L V6 24-valve (about 200 PS) and sport-tuned suspension. In 1993 Alfa even offered an all-wheel-drive model (the “164 Q4”) with a viscous-coupling AWD system. In total about 273,857 Alfa 164s were made. A light facelift in 1993 created the “164 Super” with minor trim changes. The 164 was replaced by the Alfa 166 in 1998, which also marked the end of the Tipo Quattro platform after 14 years of service.
Unique features: The 164 was the most performance-oriented car of the quartet. Besides its sharp design, it introduced advanced electronics (multiple onboard control modules) and became a testbed for tech like variable-damping suspension in the Quadrifoglio models. Alfa’s rich sound and driving character set it apart. It was also the last Alfa sold in the United States until decades later. The 164’s special trims (QV, Lusso, RZ) and optional AWD make it the Type Four model with the most sporting pedigree.
Comparison and Legacy
Though the Fiat Croma, Saab 9000, Lancia Thema, and Alfa Romeo 164 were all born from the same engineering foundation, each evolved into a distinct expression of its brand’s philosophy. The Fiat Croma embraced practicality and innovation, standing out as the most utilitarian of the group. It didn’t chase luxury or sportiness, but rather served as a reliable, spacious, and efficient car — especially with its pioneering use of common-rail diesel technology.
The Saab 9000 took a different path, reinforcing the shared platform with a focus on safety, solidity, and high-speed stability. It felt the most overengineered, with a heavy but reassuring presence. Saab’s trademark turbocharged engines gave it a lively edge, and the high-performance Aero variants proved that Scandinavian restraint could coexist with spirited driving.
Lancia’s Thema exuded a quiet sophistication. It wasn’t the most dynamic or technically radical, but it was arguably the most elegant. With plush interiors, refined manners, and a broad engine range, it fulfilled the role of an Italian luxury sedan with ease. The Thema 8·32, with its Ferrari-derived V8, brought flair and drama to the range — a bold experiment that still captures imaginations today.
Lastly, the Alfa Romeo 164 stood apart as the most emotionally charged of the four. With striking Pininfarina styling, sharp handling, and a growling V6, it wore its heart on its sleeve. While it arrived later than the others, it introduced technological refinements and performance upgrades that pushed the Type Four chassis to its limits. The 164, especially in its Quadrifoglio Verde and Q4 variants, remains the most enthusiast-oriented car of the group.
Despite their shared roots, these four vehicles demonstrated how a common platform could yield vastly different results when shaped by distinct design languages and engineering priorities. Each brought something unique to the table, and together they created one of the most successful examples of platform-sharing in European automotive history.
Conclusion
The Progetto Tipo 4 project wasn’t just a cost-saving exercise — it was a masterclass in collaborative innovation. It proved that with thoughtful engineering and creative vision, carmakers could share underpinnings without sacrificing identity. The result was four vehicles that stood independently in their markets while quietly sharing a mechanical heart.
Today, they are remembered not just for their individual strengths but for what they represented collectively: a rare moment in the automotive world when partnership across borders and brands produced cars that were greater than the sum of their parts. The legacy of the Tipo Quattro lives on in the enthusiasts who continue to celebrate their charm, quirks, and lasting impact on European car design.
