The Peugeot XN1T is a 1,580 cc, inline‑four petrol engine produced between 1986 and 1992. It features a single overhead camshaft (SOHC) and two valves per cylinder, prioritising cost — effective manufacturing and adequate performance for its era. Equipped with a twin — choke carburettor for fuel delivery, it produces approximately 55 kW (75 PS) and 120 Nm of torque, offering a balance of drivability and fuel economy for compact family cars.
Fitted primarily to the Peugeot…
Production years 1986–1992 meet pre-Euro emissions standards as per applicable French and EU regulations of the time (UTAC Type Approval records).
The Peugeot XN1T is a 1,580 cc inline‑four petrol engine engineered for compact family sedans and hatchbacks (1986-1992). It combines a simple SOHC valvetrain with carburetted fuel delivery to deliver smooth, predictable power and respectable fuel economy. Designed to meet the emissions standards of its era, it prioritises mechanical simplicity and ease of service.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,580 cc | |
Fuel type | Petrol | |
Configuration | Inline‑4, SOHC, 8‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 78.0 mm × 82.6 mm | |
Power output | 55 kW (75 PS) @ 5,500 rpm | |
Torque | 120 Nm @ 3,000 rpm | |
Fuel system | Solex 35/35 DIDTA twin-choke carburettor | |
Emissions standard | Pre-Euro (1980s/90s French/EU) | |
Compression ratio | 9.2:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven camshaft | |
Oil type | Mineral 15W-40 (API SF/CC) | |
Dry weight | 105 kg |
The Peugeot XN1T was used across Peugeot's compact platforms with transverse mounting. This engine received minor platform-specific adaptations-primarily in ancillary bracketry and exhaust routing between the 309 and 405-but remained fundamentally interchangeable. All adaptations are documented in OEM technical bulletins.
The XN1T's primary reliability consideration is carburettor maintenance, with elevated incidence of running issues in neglected examples. Peugeot service data indicates that a majority of drivability complaints for this engine family stem from carburettor faults or ignition system wear. Regular adjustment and using clean fuel make long-term ownership straightforward.
Analysis derived from Peugeot technical bulletins (1986-1992) and owner club maintenance logs. 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
Yes, the XN1T is fundamentally a robust and simple engine. Its long-term reliability heavily depends on consistent maintenance, particularly of the carburettor and ignition system. With proper care, including regular oil changes and timely replacement of wear items, it can easily exceed 200,000 km.
The most frequent issues are carburettor-related (hesitation, stalling, uneven running), ignition system failures (points, condenser), and minor oil or coolant leaks from aged gaskets and hoses. These are well-documented in Peugeot service literature and are generally inexpensive to fix.
The XN1T was primarily used in the Peugeot 309 (from 1986-1992) and the early Peugeot 405 (Phase I from 1987-1992). It was the carburetted 1.6-litre petrol engine for these popular compact models.
Modest gains are possible. Common upgrades include fitting a performance air filter, re-jetting the carburettor, and installing a free-flow exhaust. Significant power increases are difficult without major internal modifications, which are often not cost-effective for this engine.
Good for its time and configuration. In a Peugeot 405, expect around 7.5 L/100km (38 mpg UK) combined in real-world driving. The lighter 309 could achieve slightly better figures, often in the 7.0-7.5 L/100km (38-40 mpg UK) range under careful driving conditions.
No. The XN1T is a non-interference engine. If the timing chain were to break, the pistons and valves would not collide, preventing catastrophic internal damage. This is a significant safety feature for an older engine design.
Peugeot originally specified a mineral 15W-40 oil meeting API SF/CC standards. For a well-maintained, older engine, a high-quality mineral or semi-synthetic 15W-40 or 10W-40 is still suitable. Always consult your specific owner's manual for recommendations.
Comprehensive technical documentation and regulatory references
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PEUGEOT Official Site
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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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