The Renault 25 (B29) 2.5 i V6 Turbo, produced between 1990 and 1992, represented the performance pinnacle of the B29 generation Renault 25. This variant, a five-door hatchback, was positioned as the premium offering within the 25 lineup, boasting a turbocharged V6 engine and a focus on delivering a refined driving experience. The B29 series, launched in 1984, was Renault’s large family car, competing with vehicles like the Ford Granada and Opel/Vauxhall Senator. The 2.5 i V6 Turbo was the flagship model, intended to showcase Renault’s engineering capabilities and provide a more sporting alternative to the naturally aspirated engines available.
Powertrain & Engine Architecture
The heart of the Renault 25 2.5 i V6 Turbo is the Z7U engine, a 2.5-liter (2458 cc) 90-degree V6. This engine is distinguished by its use of a turbocharger and multi-port fuel injection, significantly boosting power output compared to the naturally aspirated versions. The Z7U engine produces 210 horsepower at 5500 rpm and 290 Nm (213.89 lb-ft) of torque at 2500 rpm. This configuration provided a substantial power-to-weight ratio for its time. The engine features a single overhead camshaft (OHC) valvetrain with two valves per cylinder. The compression ratio is 8.1:1. The fuel injection system is a Bosch Motronic system, managing both fuel delivery and ignition timing. Engine oil capacity is 5.8 liters (6.13 US quarts / 5.1 UK quarts), and the recommended coolant capacity is 9.8 liters (10.36 US quarts / 8.62 UK quarts).
Transmission
Unlike some versions of the Renault 25 which offered automatic transmission options, the 2.5 i V6 Turbo was exclusively equipped with a five-speed manual gearbox. This was a deliberate choice by Renault to enhance the driving experience and allow drivers to fully exploit the engine’s performance potential. The gearbox was designed to handle the increased torque output of the turbocharged engine, featuring robust internal components. The gear ratios were tailored to provide strong acceleration and comfortable cruising speeds.
Driving Characteristics
The Renault 25 2.5 i V6 Turbo offered a noticeably different driving experience compared to the lower-powered variants. Acceleration from 0 to 100 km/h (0-62 mph) was achieved in 7.4 seconds, and 0 to 60 mph in approximately 7 seconds. Top speed was rated at 233 km/h (144.78 mph). The turbocharger provided a surge of power in the mid-range, making overtaking maneuvers effortless. While the chassis was relatively conventional, the combination of the powerful engine and manual transmission resulted in a responsive and engaging driving experience. The front-wheel-drive layout, however, could exhibit torque steer under hard acceleration. The suspension, while comfortable, was tuned to provide a reasonable level of body control, although it wasn’t as overtly sporty as some contemporary rivals.
Equipment & Trim Levels
As the flagship model, the 2.5 i V6 Turbo came generously equipped. Standard features typically included central locking, electric windows, power steering, and an upgraded interior trim. The interior featured comfortable seating, often upholstered in velour or leather (leather was typically an optional extra). The dashboard layout was functional and well-designed, with clear instrumentation. Optional extras included a sunroof, upgraded audio system, and alloy wheels. The exterior styling was relatively understated, with subtle badging to denote the Turbo variant. The car’s interior space was generous, offering ample room for five passengers and a sizable trunk.
Chassis & Braking
The Renault 25 2.5 i V6 Turbo utilized a front-engine, front-wheel-drive layout. Suspension consisted of coil springs all around, with an independent front suspension and a semi-independent rear suspension. The front brakes were ventilated discs, providing ample stopping power, while the rear brakes were solid discs. An Anti-lock Braking System (ABS) was standard, enhancing safety and stability during braking. The steering was a rack and pinion system with hydraulic power assistance, offering precise and responsive steering feel. The car rode on 205/55 R16 tires mounted on 16-inch alloy wheels.
Market Reception & Comparison
The Renault 25 2.5 i V6 Turbo was generally well-received by automotive critics, who praised its powerful engine, comfortable ride, and generous equipment levels. However, some criticisms were leveled at its relatively high price and the potential for torque steer. Compared to other trims in the Renault 25 lineup, the 2.5 i V6 Turbo offered significantly higher performance but at the cost of increased fuel consumption. Fuel economy figures were 14.7 l/100 km (16 US mpg / 19.2 UK mpg) in urban driving, 7.6 l/100 km (30.9 US mpg / 37.2 UK mpg) on the extra-urban cycle, and 9.6 l/100 km (24.5 US mpg / 29.4 UK mpg) combined. Compared to the 2.0-liter and 2.2-liter versions, the Turbo offered a substantial performance advantage, but the naturally aspirated engines were more fuel-efficient and generally less expensive to maintain.
Technical Specifications
| Brand | Renault |
| Model | 25 |
| Generation | 25 (B29) |
| Type (Engine) | 2.5 i V6 Turbo (210 Hp) |
| Start of production | 1990 |
| End of production | 1992 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 14.7 l/100 km (16 US mpg / 19.2 UK mpg) |
| Fuel consumption (extra urban) | 7.6 l/100 km (30.9 US mpg / 37.2 UK mpg) |
| Fuel consumption (combined) | 9.6 l/100 km (24.5 US mpg / 29.4 UK mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 7.4 sec |
| Acceleration 0 – 62 mph | 7.4 sec |
| Acceleration 0 – 60 mph | 7 sec |
| Maximum speed | 233 km/h (144.78 mph) |
| Weight-to-power ratio | 6.7 kg/Hp |
| Weight-to-torque ratio | 4.9 kg/Nm |
| Power | 210 Hp @ 5500 rpm |
| Torque | 290 Nm @ 2500 rpm (213.89 lb.-ft. @ 2500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Z7U |
| Engine displacement | 2458 cm3 (150 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 91 mm (3.58 in.) |
| Piston Stroke | 63 mm (2.48 in.) |
| Compression ratio | 8.1:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Turbocharger |
| Valvetrain | OHC |
| Engine oil capacity | 5.8 l (6.13 US qt | 5.1 UK qt) |
| Coolant capacity | 9.8 l (10.36 US qt | 8.62 UK qt) |
| Kerb Weight | 1410 kg (3108.52 lbs.) |
| Max. weight | 1870 kg (4122.64 lbs.) |
| Max load | 460 kg (1014.13 lbs.) |
| Trunk (boot) space – minimum | 440 l (15.54 cu. ft.) |
| Trunk (boot) space – maximum | 1240 l (43.79 cu. ft.) |
| Fuel tank capacity | 72 l (19.02 US gal | 15.84 UK gal) |
| Length | 4715 mm (185.63 in.) |
| Width | 1805 mm (71.06 in.) |
| Height | 1415 mm (55.71 in.) |
| Wheelbase | 2725 mm (107.28 in.) |
| Front track | 1495 mm (58.86 in.) |
| Rear track | 1475 mm (58.07 in.) |
| Drivetrain | Front wheel drive |
| Number of gears | 5 |
| Gearbox type | Manual transmission |
| Front suspension | Coil spring |
| Rear suspension | Coil spring |
| 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 | 205/55 R16 |
| Wheel rims size | 16 |
Legacy
Today, the Renault 25 2.5 i V6 Turbo is a relatively rare and sought-after classic car. Its turbocharged engine and sporty driving characteristics have earned it a following among enthusiasts. While maintenance can be more complex and expensive than with the lower-powered variants, the Z7U engine is generally considered to be robust when properly maintained. Rust can be a significant issue with these cars, as with many vehicles of this era. Values have been steadily increasing in recent years, reflecting its status as a desirable and distinctive French performance car. The 2.5 i V6 Turbo represents a high point in Renault’s engineering history and a testament to the brand’s ability to create engaging and sophisticated automobiles.
