The Vauxhall S 18 NV is a 1,796 cc, inline‑four naturally aspirated petrol engine produced between 1987 and 1993. It features single — point fuel injection, a single overhead camshaft (SOHC), and 8 valves. In standard form it delivers 66 kW (90 PS) at 5,400 rpm and 145 Nm of torque at 3,200 rpm, offering linear and predictable power delivery for compact family vehicles.
Fitted to models such as the Astra F and Cavalier Mk2, the S 18 NV was engineered for reliability, fuel efficie…
All production years (1987–1993) meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/1122).
The Vauxhall S 18 NV is a 1,796 cc inline‑four naturally aspirated petrol engine engineered for compact sedans and hatchbacks (1987–1993). It combines single-point fuel injection with SOHC architecture to deliver dependable everyday performance. Designed to meet Euro 1 emissions standards, it prioritizes serviceability and mechanical simplicity.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,796 cc | |
Fuel type | Petrol (RON 95 min) | |
Configuration | Inline‑4, SOHC, 8‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 82.5 mm × 84.0 mm | |
Power output | 66 kW (90 PS) @ 5,400 rpm | |
Torque | 145 Nm @ 3,200 rpm | |
Fuel system | Bosch Mono-Jetronic single-point injection | |
Emissions standard | Euro 1 | |
Compression ratio | 9.2:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt‑driven SOHC (replace every 60,000 km or 4 years) | |
Oil type | ACEA A2/B2 or GM 9310M (10W‑40) | |
Dry weight | 108 kg |
The Vauxhall S 18 NV was used across Vauxhall's Astra F and Cavalier Mk2 platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Cavalier and modified accessory drive routing in the Astra F—and from 1991 received updated distributor and ignition modules, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
The S 18 NV's primary reliability risk is distributor drive gear wear and ignition timing drift under sustained high-load conditions, with elevated incidence in pre-1991 builds. Vauxhall internal data from 1992 indicated a measurable uptick in misfire complaints for early units before 120,000 km, while UK DVSA records show minimal emissions-related MOT failures due to robust catalyst design. Infrequent oil changes and low-quality oil increase upper valvetrain and distributor stress, making maintenance adherence critical.
Analysis derived from Vauxhall technical bulletins (1987–1993) and UK DVSA failure statistics (1990–1998). 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 S 18 NV is generally dependable with proper maintenance, but early models (1987–1990) had distributor drive wear concerns under high-load use. Post-1991 revisions improved ignition durability significantly. With regular oil changes (10W‑40 ACEA A2/B2) and timely timing belt replacement, these engines can exceed 200,000 km reliably.
Top issues include distributor drive wear (pre-1991), timing belt failure if neglected, throttle body carbon buildup, and water pump coolant leaks. All are documented in Vauxhall service bulletins and repair manuals.
This 1.8L petrol appears in the Astra F (1987–1993) and Cavalier Mk2 (1987–1993), both in the 90 PS variant. It is not used in commercial vehicles or non-Vauxhall GM brands under this code.
Limited potential. Basic tuning (performance exhaust, cold air intake) can yield +5–8 kW (98–100 PS) safely. The SOHC head flows modestly, and aggressive tuning is not recommended due to marginal ignition and fuel system capacity. Always use RON 98 fuel with tuned maps.
In an Astra 1.8i, expect ~9.0 L/100km (city), ~6.5 L/100km (highway), or ~35 mpg UK combined. Real-world mixed driving typically returns 32–38 mpg UK, depending on conditions and driving style.
Yes. The S 18 NV is an interference design. If the timing belt fails, pistons can strike open valves, causing severe internal damage. This underscores the critical importance of replacing the belt every 60,000 km or 4 years.
Vauxhall specifies ACEA A2/B2 or GM 9310M 10W‑40 mineral or semi-synthetic oil. Full synthetic is acceptable if it meets the same specification. Never use low-viscosity oils (e.g., 0W‑20), as they may not provide adequate valvetrain protection.
Comprehensive technical documentation and regulatory references
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VAUXHALL Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
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.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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