The Nissan RB25DE is a 2,492 cc, inline‑six naturally aspirated petrol engine produced between 1993 and 1998. It features a cast — iron block, aluminium cylinder head, and dual overhead camshafts with 24 valves. In standard form for the R33 Skyline and Stagea, it delivered 140 kW (190 PS) and 234 Nm of torque, providing smooth, linear power delivery ideal for grand touring.
Fitted primarily to the R33 Skyline sedan and coupe, as well as the WNC34 Stagea wagon, the RB25DE was en…
Production years 1993–1998 meet applicable Japanese and ADR standards for their model year (VCA UK Type Approval not applicable for this non-EU market engine).
The Nissan RB25DE is a 2,492 cc inline‑six naturally aspirated petrol engine engineered for sports sedans and wagons (1993-1998). It combines electronic fuel injection with DOHC 24-valve architecture to deliver smooth, high-revving power and refined grand touring capability. Designed to meet 1990s emissions standards, it balances performance with the technology of its era.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,492 cc | |
Fuel type | Petrol | |
Configuration | Inline-6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 86.0 mm × 71.5 mm | |
Power output | 140 kW (190 PS) @ 6,000 rpm | |
Torque | 234 Nm @ 4,800 rpm | |
Fuel system | Electronic Fuel Injection (Multi-point) | |
Emissions standard | 1990s Japanese / ADR standards | |
Compression ratio | 10.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven (single-row) | |
Oil type | SAE 10W-30 or 10W-40 | |
Dry weight | 195 kg |
The Nissan RB25DE was used exclusively in Nissan's R33/WNC34 platforms with longitudinal rear-wheel-drive mounting. This engine received specific adaptations for the Stagea wagon, including a unique engine wiring harness and accessory bracketry. All adaptations are documented in OEM technical bulletins.
The RB25DE's primary reliability risk is timing chain tensioner and guide wear, with elevated incidence in vehicles subjected to high-RPM use or infrequent oil changes. Nissan Service Bulletin NTB95-067 details the issue, while owner reports frequently cite ignition coil failure as a secondary cause of misfires. Adherence to strict oil change intervals and using quality oil make chain longevity critical.
Analysis derived from Nissan technical bulletins (1993-1998) and owner-reported failure data (1999-2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The RB25DE is renowned for its durability and smoothness. Its main weakness is the timing chain tensioner, which requires attention. With regular oil changes, fresh ignition coils, and preventative replacement of the tensioner/guides, an RB25DE can be extremely reliable and last well beyond 300,000 km.
The most frequent issues are timing chain tensioner and guide wear (causing rattle), ignition coil failure (causing misfires), coolant leaks from the plastic thermostat housing, and oil leaks from the valve cover gasket. These are well-documented in Nissan service bulletins.
The RB25DE was used in the R33 generation Nissan Skyline (1993-1998) and the first-generation (WNC34) Nissan Stagea (1996-1998). It was not used in any other Nissan production vehicles or licensed to other manufacturers.
Yes, the RB25DE responds well to tuning. Common upgrades include a performance camshaft, intake and exhaust systems, and ECU remapping. Power gains of 20-30 kW are achievable reliably. The bottom end is very strong, making it a popular base for turbo conversions (to RB25DET specification).
Fuel economy is moderate for a 2.5L inline-six. Expect around 10-12 L/100km (24-28 mpg US) in combined driving for a Skyline. The heavier Stagea wagon will be closer to 11-13 L/100km (22-26 mpg US). Real-world figures depend heavily on driving style.
Yes. The RB25DE is an interference engine. If the timing chain fails or jumps, the pistons will contact the valves, causing severe internal engine damage. This makes preventative maintenance of the timing components critical.
Nissan originally specified SAE 10W-30 or 10W-40. For high-RPM applications, a high-quality 10W-40 semi-synthetic or full synthetic oil is strongly recommended for better protection. Change intervals should be kept strict, around 5,000-8,000 km.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
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