The Citroën CX I Prestige 2400 Injection Cmatic, produced between 1977 and 1980, represents a high-water mark in Citroën’s long history of innovative automotive engineering. Positioned as a premium variant within the first generation (Series I) of the CX range, designated 1HX0, this model combined a sophisticated fuel-injected 2.4-liter inline-four engine with Citroën’s advanced Cmatic automatic transmission. The CX, intended as a replacement for the venerable DS, aimed to offer a similar level of comfort and technological advancement, but in a more modern and aerodynamically efficient package. The Prestige trim level signified a higher level of luxury and equipment compared to the base CX models.
Technical Specifications
| Brand | Citroen |
| Model | CX |
| Generation | CX I |
| Type | Prestige 2400 (128 Hp) Injection Cmatic |
| Start of production | 1977 |
| End of production | 1980 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 13.5 sec |
| Acceleration 0 – 62 mph | 13.5 sec |
| Acceleration 0 – 60 mph | 12.8 sec |
| Maximum speed | 180 km/h (111.85 mph) |
| Weight-to-power ratio | 11.6 kg/Hp, 85.9 Hp/tonne |
| Weight-to-torque ratio | 7.6 kg/Nm, 132.2 Nm/tonne |
| Power | 128 Hp @ 4800 rpm |
| Power per litre | 54.5 Hp/l |
| Torque | 197 Nm @ 3600 rpm (145.3 lb.-ft. @ 3600 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | M23.622 |
| Engine displacement | 2347 cm3 (143.22 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 93.5 mm (3.68 in.) |
| Piston Stroke | 85.5 mm (3.37 in.) |
| Compression ratio | 9:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated |
| Engine oil capacity | 5.3 l (5.6 US qt | 4.66 UK qt) |
| Coolant | 11 l (11.62 US qt | 9.68 UK qt) |
| Kerb Weight | 1490 kg (3284.89 lbs.) |
| Max. weight | 1925 kg (4243.9 lbs.) |
| Max load | 435 kg (959.01 lbs.) |
| Trunk (boot) space – minimum | 325 l (11.48 cu. ft.) |
| Fuel tank capacity | 68 l (17.96 US gal | 14.96 UK gal) |
| Length | 4916 mm (193.54 in.) |
| Width | 1734 mm (68.27 in.) |
| Height | 1357 mm (53.43 in.) |
| Wheelbase | 3095 mm (121.85 in.) |
| Front track | 1474 mm (58.03 in.) |
| Rear track | 1360 mm (53.54 in.) |
| Front overhang | 1057 mm (41.61 in.) |
| Rear overhang | 764 mm (30.08 in.) |
| Ride height (ground clearance) | 155 mm (6.1 in.) |
| Drag coefficient (Cd) | 0.37 |
| Minimum turning circle | 11.80 m (38.71 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the front wheels of the vehicle. |
| Drive wheel | Front wheel drive |
| Number of gears and type of gearbox | 3 gears, automatic transmission |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Steering type | Steering rack and pinion |
| Wheel rims size | 5.5J x 14 |
Introduction
The Citroën CX I Prestige 2400 Injection Cmatic was a flagship model within the initial CX lineup, produced from 1977 to 1980. The CX, internally designated as the 1HX0 series, was a radical departure from its predecessor, the DS, featuring a more modern, aerodynamic design penned by Robert Opron. The Prestige trim represented the highest level of luxury available at the time, offering a refined driving experience and a host of comfort features. This variant aimed to appeal to buyers seeking a sophisticated and technologically advanced grand tourer.
Powertrain & Engine Architecture
At the heart of the CX 2400 Injection Cmatic lies the M23.622 engine, a 2.4-liter (2347 cc) inline-four cylinder powerplant. This engine featured a cast iron block and an aluminum cylinder head, employing a two-valve-per-cylinder configuration. Crucially, this version of the engine utilized Bosch multi-port fuel injection, a significant upgrade over the carbureted versions found in lower-spec CX models. This injection system, combined with a compression ratio of 9:1, allowed the engine to produce 128 horsepower at 4800 rpm and 197 Nm (145.3 lb-ft) of torque at 3600 rpm. The engine’s transverse mounting and front-wheel drive configuration were hallmarks of Citroën’s engineering philosophy. The Cmatic transmission was a three-speed automatic, notable for its electro-hydraulic control system. Unlike conventional automatics, the Cmatic offered a degree of manual override, allowing the driver to select different gear ranges, though it lacked a traditional gear selector.
Driving Characteristics
The CX 2400 Injection Cmatic offered a unique driving experience, heavily influenced by Citroën’s renowned hydropneumatic suspension system. This system provided an exceptionally smooth and comfortable ride, absorbing bumps and imperfections in the road with remarkable ease. However, the combination of the 128 hp engine and the three-speed automatic transmission resulted in performance that was more relaxed than sporty. Acceleration to 60 mph took around 12.8 seconds, and top speed was approximately 112 mph. The Cmatic transmission, while innovative, could feel somewhat hesitant and lacked the responsiveness of a modern automatic or a manual gearbox. Gear ratios were optimized for cruising comfort rather than outright acceleration. Compared to the more powerful CX 2500 GTI with a manual transmission, the 2400 Injection Cmatic felt noticeably slower, but it offered a more effortless and refined driving experience, particularly on long journeys.
Equipment & Trim Levels
The Prestige trim level equipped the CX 2400 Injection Cmatic with a generous array of standard features. Interior appointments included comfortable velour upholstery, wood veneer trim on the dashboard and door panels, and power-assisted steering. Additional features included central locking, electric windows, and a high-quality radio. Optional extras included air conditioning, a sunroof, and upgraded sound systems. The dashboard layout was characteristically Citroën, featuring a unique combination of analog gauges and illuminated switches. The CX’s steering wheel, with its distinctive five spokes, was another defining feature of the interior.
Chassis & Braking
The CX I utilized a monocoque chassis construction, providing a rigid and lightweight platform. The hydropneumatic suspension system, with self-leveling and height-adjustable features, was a key component of the chassis design. The front suspension employed independent double wishbones, while the rear suspension utilized a trailing arm setup. Braking duties were handled by ventilated discs at the front and solid discs at the rear, providing adequate stopping power for the vehicle’s weight and performance. The steering system was a rack and pinion type, offering precise and responsive handling.
Market Reception & Comparison
The Citroën CX I Prestige 2400 Injection Cmatic was generally well-received by automotive critics, who praised its ride comfort, innovative technology, and stylish design. However, some reviewers noted the relatively modest performance and the complexity of the Cmatic transmission. Compared to other luxury cars of the era, such as the Mercedes-Benz W116 and the BMW E23, the CX offered a unique and distinctly French alternative. Fuel economy was reasonable for the time, averaging around 20-25 mpg. Reliability was a mixed bag; the hydropneumatic suspension system, while offering exceptional comfort, could be prone to leaks and required specialized maintenance. The fuel injection system, while improving performance, also added to the complexity of the engine.
Legacy
The Citroën CX I Prestige 2400 Injection Cmatic remains a highly sought-after classic car today, appreciated for its innovative engineering, distinctive styling, and comfortable ride. The M23 engine, while not known for its outright power, is generally considered to be a reliable unit when properly maintained. The Cmatic transmission, however, can be a source of problems, and finding qualified technicians to service it can be challenging. In the used car market, well-maintained examples of the CX 2400 Injection Cmatic command premium prices, reflecting their rarity and historical significance. The CX represents a high point in Citroën’s history, showcasing the company’s commitment to innovation and its ability to create truly unique and memorable automobiles.
