1985-1995 Nissan Skyline VII (R31) 2.5 i R6 24V (180 Hp)

The Nissan Skyline VII (R31), produced from 1985 to 1995, represents a significant evolution in the Skyline lineage. Moving away from the more traditional sedan styling of previous generations, the R31 aimed to blend luxury, technology, and performance, paving the way for the iconic R32 GT-R. This article focuses specifically on the Nissan Skyline VII (R31) 2.5 i R6 24V (180 Hp) variant, a model that offered a compelling balance of refinement and power within the broader R31 range, which utilized the 1HX0/A3 platform. While not officially sold in the United States, the R31 gained a following through enthusiast imports, becoming a respected vehicle in the JDM (Japanese Domestic Market) scene.

Powertrain & Engine Architecture

The Nissan Skyline VII (R31) 2.5 i R6 24V (180 Hp) is powered by a 2.5-liter (2498 cc / 152.44 cubic inches) naturally aspirated inline-six engine, belonging to Nissan’s renowned RB-series. Specifically, this variant utilizes the RB25DE engine code. The RB25DE features a cast iron block and an aluminum cylinder head, contributing to its durability and relatively lightweight construction. It employs a multi-port fuel injection system, delivering precise fuel metering for efficient combustion. The engine boasts a 10:1 compression ratio, optimized for use with gasoline fuel.

The valvetrain consists of dual overhead camshafts (DOHC) operating four valves per cylinder (24 valves total), enhancing volumetric efficiency and contributing to the engine’s power output. The engine’s lubrication system is a conventional wet sump design, ensuring reliable oil circulation. The RB25DE is known for its robust construction and ability to withstand moderate performance modifications. The transmission paired with this engine is a 5-speed manual transmission, providing a direct and engaging driving experience. This transmission features a rear-wheel-drive configuration, a classic layout favored by enthusiasts for its balanced handling characteristics.

Driving Characteristics

The 180 hp and 166.69 lb-ft of torque produced by the RB25DE in the R31 2.5 i R6 24V delivers a smooth and linear power delivery. Compared to the lower-powered 1.8L variants, the 2.5L offered a noticeable improvement in acceleration and overall responsiveness. However, it didn’t possess the raw power of the later turbocharged RB25DET found in the GTS-R model. The 5-speed manual transmission allows for precise gear selection, maximizing the engine’s potential. The gear ratios are tuned for a balance between acceleration and cruising efficiency.

In real-world driving, the R31 2.5 i R6 24V feels planted and stable, thanks to its rear-wheel-drive layout and well-tuned suspension. While not a dedicated sports car, it offers a satisfying driving experience, particularly on winding roads. The engine’s torque peak at 5200 rpm provides ample pulling power for overtaking maneuvers and maintaining highway speeds. Compared to the automatic transmission options available on other R31 models, the manual transmission provides a more connected and engaging driving experience, allowing the driver to fully control the engine’s power.

Equipment & Trim Levels

The Nissan Skyline VII (R31) 2.5 i R6 24V typically served as a mid-range trim level within the R31 lineup. Standard equipment included power steering, ventilated front disc brakes, and disc brakes on all four wheels. Interior features generally consisted of cloth upholstery, a basic stereo system, and manual air conditioning. The dashboard layout was functional and straightforward, reflecting the design aesthetic of the mid-1980s.

Optional extras available for this trim included power windows, power locks, an upgraded stereo system, and a sunroof. Higher-spec R31 models, such as the GTS-R, offered more luxurious features like leather upholstery, automatic climate control, and advanced audio systems. The 2.5 i R6 24V aimed to provide a comfortable and well-equipped driving experience without the premium price tag of the top-of-the-line models.

Chassis & Braking

The R31 2.5 i R6 24V utilizes a MacPherson strut suspension system at the front and a multi-link suspension at the rear. This suspension setup provides a good balance between ride comfort and handling performance. The front suspension incorporates coil springs and shock absorbers, while the rear suspension utilizes coil springs, shock absorbers, and trailing arms. Stabilizer bars are fitted to both the front and rear axles, reducing body roll during cornering.

The braking system consists of ventilated disc brakes at the front and solid disc brakes at the rear. ABS (Anti-lock Braking System) was available as an option, enhancing braking performance and safety. The R31’s chassis is a robust unibody construction, providing a solid foundation for the suspension and braking systems. The steering system is a hydraulic power steering system, offering effortless maneuverability.

Market Reception & Comparison

The Nissan Skyline VII (R31) 2.5 i R6 24V was generally well-received by automotive critics in Japan and Australia. It was praised for its smooth engine, comfortable ride, and well-balanced handling. However, some critics noted that it lacked the outright performance of the turbocharged models. Fuel economy was considered competitive for a 2.5-liter inline-six engine, averaging around 16.8 US mpg in urban conditions and 26.1 US mpg on the highway.

Compared to the lower-powered 1.8L variants, the 2.5 i R6 24V offered a significant performance upgrade, making it a more appealing option for drivers who prioritized power and responsiveness. However, it was more expensive to purchase and maintain than the 1.8L models. The 2.5 i R6 24V also offered a more refined driving experience than the 1.9 TDI diesel variants, which were primarily focused on fuel efficiency. Reliability was generally good, with the RB25DE engine proving to be a durable and long-lasting powerplant.

Technical Specifications

Legacy

The Nissan Skyline VII (R31) 2.5 i R6 24V, while often overshadowed by its successors, remains a respected vehicle among enthusiasts. The RB25DE engine is known for its durability and potential for modification, making it a popular choice for tuners. The R31’s robust construction and relatively simple mechanical design contribute to its long-term reliability. In the used car market, well-maintained R31 2.5 i R6 24V models are becoming increasingly collectible, particularly those with low mileage and original features. The R31 represents a pivotal moment in Skyline history, bridging the gap between the traditional sedans and the high-performance machines that would define the brand in the years to come. Its blend of comfort, performance, and reliability ensures its continued appeal to enthusiasts for years to come.