The Citroen CX II 25 RD Turbo, produced between 1985 and 1987, represented a compelling blend of luxury, performance, and advanced technology within the CX range. Positioned as a mid-range offering in the CX II lineup, it aimed to provide a more spirited driving experience than the naturally aspirated diesel models while remaining more accessible than the flagship 25 GTI Turbo. This variant utilized a turbocharged 2.5-liter inline-four diesel engine, delivering 95 horsepower and 216 Nm (159.31 lb-ft) of torque. It was a key model for Citroen in Europe, appealing to buyers seeking a comfortable, efficient, and relatively quick long-distance cruiser.
Technical Specifications
| Brand | Citroen |
| Model | CX |
| Generation | CX II |
| Type (Engine) | 25 RD Turbo (95 Hp) |
| Start of production | 1985 |
| End of production | 1987 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 8.6 l/100 km (27.4 US mpg, 32.8 UK mpg, 11.6 km/l) |
| Fuel consumption (extra urban) | 5.6 l/100 km (42 US mpg, 50.4 UK mpg, 17.9 km/l) |
| Fuel consumption (combined) | 7.1 l/100 km (33.1 US mpg, 39.8 UK mpg, 14.1 km/l) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 13.3 sec |
| Acceleration 0 – 62 mph | 13.3 sec |
| Acceleration 0 – 60 mph | 12.6 sec |
| Maximum speed | 178 km/h (110.6 mph) |
| Weight-to-power ratio | 14.8 kg/Hp, 67.6 Hp/tonne |
| Weight-to-torque ratio | 6.5 kg/Nm, 153.7 Nm/tonne |
| Power | 95 Hp @ 3700 rpm |
| Power per litre | 38 Hp/l |
| Torque | 216 Nm @ 2000 rpm (159.31 lb.-ft. @ 2000 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | M25-648 |
| Engine displacement | 2500 cm3 (152.56 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 93 mm (3.66 in.) |
| Piston Stroke | 92 mm (3.62 in.) |
| Compression ratio | 22.25:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Precombustion chamber injection |
| Engine aspiration | Turbocharger |
| Engine oil capacity | 6 l (6.34 US qt | 5.28 UK qt) |
| Coolant | 12.5 l (13.21 US qt | 11 UK qt) |
| Kerb Weight | 1405 kg (3097.49 lbs.) |
| Max. weight | 1905 kg (4199.81 lbs.) |
| Max load | 500 kg (1102.31 lbs.) |
| Trunk (boot) space – minimum | 485 l (17.13 cu. ft.) |
| Trunk (boot) space – maximum | 507 l (17.9 cu. ft.) |
| Fuel tank capacity | 68 l (17.96 US gal | 14.96 UK gal) |
| Max. roof load | 80 kg (176.37 lbs.) |
| Permitted trailer load with brakes (12%) | 1300 kg (2866.01 lbs.) |
| Permitted trailer load without brakes | 700 kg (1543.24 lbs.) |
| Permitted towbar download | 100 kg (220.46 lbs.) |
| Length | 4650 mm (183.07 in.) |
| Width | 1770 mm (69.69 in.) |
| Height | 1360 mm (53.54 in.) |
| Wheelbase | 2845 mm (112.01 in.) |
| Front track | 1520 mm (59.84 in.) |
| Rear (Back) track | 1370 mm (53.94 in.) |
| Ride height (ground clearance) | 157 mm (6.18 in.) |
| Drag coefficient (Cd) | 0.35 |
| Minimum turning circle | 12.50 m (41.01 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 | 5 gears, manual transmission |
| Front suspension | Hydro-pneumatic element |
| Rear suspension | Hydro-pneumatic element |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 195/70 R14 |
| Wheel rims size | 5.5J x 14 |
Powertrain & Engine Architecture
The heart of the CX II 25 RD Turbo was the M25-648 engine, a 2.5-liter inline-four diesel. This engine utilized precombustion chamber injection, a system common in European diesels of the era, which improved combustion efficiency and reduced noise compared to direct injection. The addition of a turbocharger significantly boosted power output, bringing it to 95 horsepower. The turbocharger itself was a Garrett unit, providing a noticeable increase in torque across the rev range. The engine featured a two-valve per cylinder configuration and a relatively high compression ratio of 22.25:1, typical for diesel engines. The five-speed manual transmission was the only gearbox option available with this engine, providing a good balance between performance and fuel economy.
Driving Characteristics
The 25 RD Turbo offered a distinctly different driving experience compared to the non-turbocharged CX diesels. The turbocharger provided a substantial boost in acceleration, reducing the 0-60 mph time to around 12.6 seconds and allowing for a top speed of 178 km/h (110.6 mph). While not a sports car, the 25 RD Turbo felt considerably more responsive and capable, particularly when overtaking or climbing hills. The Citroen’s legendary hydropneumatic suspension continued to provide an exceptionally comfortable ride, absorbing bumps and imperfections in the road with ease. The five-speed manual transmission allowed drivers to keep the engine in its optimal power band, maximizing performance. However, turbo lag was noticeable, requiring drivers to anticipate acceleration and downshift accordingly.
Equipment & Trim Levels
The CX II 25 RD Turbo was generally well-equipped for its time. Standard features included power steering, ABS brakes, and comfortable cloth upholstery. The dashboard layout was typical of the CX II, featuring a combination of analog gauges and warning lights. Optional extras included leather upholstery, air conditioning, and a sunroof. The trim level was positioned as a step up from the base diesel models, offering a more refined interior and improved performance. It wasn’t as luxurious as the GTI Turbo, which featured more premium materials and additional features.
Chassis & Braking
The CX II utilized Citroen’s innovative hydropneumatic suspension system, which provided a self-leveling ride and exceptional comfort. The front suspension featured independent hydropneumatic elements, while the rear suspension also employed a hydropneumatic setup. Braking duties were handled by ventilated discs at the front and solid discs at the rear. The ABS system helped to prevent wheel lockup during hard braking, enhancing safety. The steering was a rack-and-pinion system with hydraulic power assistance, providing precise and effortless steering control.
Market Reception & Comparison
The CX II 25 RD Turbo was generally well-received by automotive critics. It was praised for its comfortable ride, strong performance, and fuel efficiency. Compared to the naturally aspirated diesel models, the 25 RD Turbo offered a significant improvement in acceleration and overall driving enjoyment. However, some critics noted the presence of turbo lag and the relatively high price compared to other diesel cars in its class. Compared to the 25 GTI Turbo, the RD Turbo offered a more economical option, sacrificing some performance and luxury in the process.
Legacy
The Citroen CX II 25 RD Turbo remains a sought-after classic car among enthusiasts. The M25-648 engine, while robust, requires regular maintenance to ensure longevity. Common issues include turbocharger wear and potential problems with the fuel injection system. However, with proper care, these engines can provide many years of reliable service. Today, the CX II 25 RD Turbo is appreciated for its unique blend of French engineering, comfort, and performance, representing a high point in Citroen’s history.
