The Citroën CX I Prestige 2400 Cmatic, produced between 1975 and 1977, represents a fascinating intersection of innovative engineering and luxury within the larger Citroën CX lineage. Positioned as a premium variant within the initial CX I series (based on the chassis code XM), the 2400 Cmatic offered a sophisticated driving experience centered around its advanced hydropneumatic suspension and a comfortable, automatic transmission. It served as a flagship model, showcasing Citroën’s technological prowess and appealing to buyers seeking a blend of performance and refinement. The CX, as a whole, was intended to replace the venerable Citroën DS, continuing the tradition of avant-garde design and engineering that defined the French automaker.
Technical Specifications
| Brand | Citroen |
| Model | CX |
| Generation | CX I |
| Type | Prestige 2400 (116 Hp) Cmatic |
| Start of production | 1975 |
| End of production | 1977 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Fuel Type | Petrol (Gasoline) |
| Maximum speed | 176 km/h (109.36 mph) |
| Weight-to-power ratio | 12.6 kg/Hp, 79.2 Hp/tonne |
| Weight-to-torque ratio | 8.1 kg/Nm, 122.9 Nm/tonne |
| Power | 116 Hp @ 5500 rpm |
| Power per litre | 49.4 Hp/l |
| Torque | 180 Nm @ 3000 rpm (132.76 lb.-ft. @ 3000 rpm) |
| Maximum engine speed | 5900 rpm |
| Engine layout | Front, Transverse |
| Engine Model/Code | M23.623 |
| 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 | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| 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 | 1465 kg (3229.77 lbs.) |
| Max. weight | 1890 kg (4166.74 lbs.) |
| Max load | 425 kg (936.96 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 Cmatic, launched in 1975, was a significant evolution in Citroën’s design philosophy. It represented the first iteration of the CX series, intended to succeed the iconic DS. The CX distinguished itself with a more aerodynamic profile, penned by Robert Opron, and a continued reliance on Citroën’s groundbreaking hydropneumatic suspension system. The “Prestige” designation indicated a higher trim level, offering enhanced comfort and features. The “Cmatique” denoted the use of Citroën’s three-speed automatic transmission, a relatively uncommon option in the European market at the time, and one that significantly altered the driving experience compared to the standard manual gearbox.
Powertrain & Engine Architecture
The heart of the CX 2400 Cmatic is the M23.623 inline-four cylinder engine, displacing 2.4 liters. This engine, while not a high-revving performance unit, was designed for smooth, reliable operation. It utilized a single overhead camshaft (SOHC) valvetrain with two valves per cylinder. Fuel delivery was managed by a Solex C35 PHH carburetor, a common setup for European vehicles of the era. The engine produced 116 horsepower at 5500 rpm and 180 Nm (132.76 lb-ft) of torque at 3000 rpm. The Cmatic transmission is a three-speed automatic, utilizing a torque converter and hydraulic control system. It was known for its smoothness but was not particularly quick-shifting by modern standards. The engine’s transverse mounting, coupled with front-wheel drive, contributed to the CX’s excellent handling characteristics.
Driving Characteristics
The CX 2400 Cmatic offered a distinctly comfortable and refined driving experience. The hydropneumatic suspension, a Citroën hallmark, provided an exceptionally smooth ride, absorbing bumps and imperfections in the road with remarkable ease. The automatic transmission, while not sporty, made for relaxed cruising. However, the combination of the 2.4-liter engine and the automatic gearbox resulted in somewhat leisurely acceleration. Compared to the manual transmission versions of the CX 2400, the Cmatic was noticeably slower. The three-speed automatic’s gear ratios were optimized for fuel efficiency and comfort rather than outright performance. The steering, aided by Citroën’s power steering system, was light and precise, contributing to the car’s ease of maneuverability.
Equipment & Trim Levels
The “Prestige” trim level of the CX 2400 Cmatic included a number of features designed to enhance comfort and convenience. Standard equipment typically included comfortable cloth upholstery, a wood-trimmed dashboard, and power-assisted steering. Optional extras could include air conditioning, a sunroof, and upgraded audio systems. The interior was spacious and well-appointed, reflecting Citroën’s commitment to providing a luxurious driving experience. The dashboard layout was characteristically Citroën, featuring a unique combination of analog gauges and toggle switches.
Chassis & Braking
The CX I utilized a monocoque chassis construction, providing a strong and rigid platform. The front suspension employed independent double wishbones, while the rear suspension relied on the hydropneumatic system, offering self-leveling and adjustable ride height. Braking duties were handled by ventilated discs at the front and solid discs at the rear. The braking system was known for its effectiveness, providing ample stopping power. The CX’s relatively low weight (1465 kg / 3229.77 lbs) contributed to its balanced handling characteristics.
Market Reception & Comparison
The Citroën CX I Prestige 2400 Cmatic was generally well-received by automotive critics, who praised its innovative suspension, comfortable ride, and stylish design. However, the automatic transmission was sometimes criticized for its lack of responsiveness. Compared to other trims in the CX lineup, such as the 2000 or the later GTI models, the 2400 Cmatic was positioned as a more luxurious and comfortable option, sacrificing some performance in the process. Fuel economy was reasonable for the time, but not exceptional. Reliability was generally good, although the complexity of the hydropneumatic suspension system could lead to occasional maintenance issues.
Legacy
The Citroën CX, and specifically the 2400 Cmatic variant, holds a special place in automotive history as a testament to Citroën’s engineering innovation and design flair. While the hydropneumatic suspension system can require specialized maintenance, the M23 engine is generally considered to be robust and reliable. Today, the CX 2400 Cmatic is a sought-after classic car, appreciated by enthusiasts for its unique character and comfortable driving experience. Finding well-maintained examples can be challenging, but the CX remains a compelling alternative to more mainstream classic cars of the era, offering a distinctly French and sophisticated driving experience.
