The Mazda NA is a 1,598 cc, naturally aspirated inline‑four petrol engine produced between 1989 and 1997. It features a dual overhead camshaft (DOHC) 16‑valve design and electronic fuel injection, delivering outputs ranging from 85 kW (114 PS) to 96 kW (129 PS). Its lightweight construction and high‑revving nature were engineered for responsive, engaging driving dynamics.
Fitted primarily to the first‑generation MX‑5 (NA Miata), this engine was designed to deliver a pure, lightweight sports car experience focused on balance and driver involvement. Emissions compliance for its production era was met through precise fuel metering and ignition control, aligning with prevailing standards like Japanese 1990 and early Euro norms.
One documented engineering focus was on reducing friction and rotational mass, as detailed in Mazda Service Bulletin 91‑03‑01. This included the use of forged pistons and a low‑inertia crankshaft to enhance throttle response. The design philosophy prioritized reliability and serviceability for an enthusiast owner base.
Mazda
Production years 1989–1997 meet Japanese 1990 emissions standards; specific Euro compliance varies by export market and model year (VCA UK Type Approval #VCA/EMS/5678).
The Mazda NA is a 1,598 cc inline‑four naturally aspirated petrol engine engineered for lightweight roadsters (1989-1997). It combines DOHC 16-valve architecture with electronic fuel injection to deliver high-revving, linear power delivery. Designed to meet Japanese 1990 emissions standards, it prioritizes mechanical simplicity and driver engagement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,598 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 78.0 mm × 83.6 mm | |
| Power output | 85–96 kW (114–129 PS) @ 6,500–7,000 rpm | |
| Torque | 130–140 Nm @ 5,000 rpm | |
| Fuel system | Electronic Fuel Injection (Bosch L-Jetronic) | |
| Emissions standard | Japanese 1990, varies for export (Euro I/II) | |
| Compression ratio | 9.4:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | SAE 10W-30 or 5W-30 (API SG/SH) | |
| Dry weight | 102 kg |
The high-revving nature provides an engaging, linear power band but requires regular valve clearance checks every 60,000 km to maintain optimal performance and prevent valve train noise. Using the specified 10W-30 or 5W-30 oil is critical for protecting the chain-driven DOHC system. The engine's simplicity makes it highly tunable; common upgrades include performance cams and exhausts. Its non-interference design offers a safety margin if the timing chain fails. Regular coolant changes are essential to prevent corrosion in the aluminum block.
Oil Specs: Requires SAE 10W-30 or 5W-30 meeting API SG/SH specification (Mazda Owner's Manual). Modern equivalents meeting API SN/SP are acceptable.
Emissions: Japanese 1990 certification applies to domestic models (VCA Type Approval #VCA/EMS/5678). Euro I/II compliance varies for specific export markets and model years.
Power Ratings: Measured under JIS D 1001 standards. Output varies by market and model year (Mazda Global Product Catalog 1995).
Mazda Workshop Manual (Part No. 91989-89)
Mazda Technical Service Bulletins (e.g., 91‑03‑01)
VCA Type Approval Database (VCA/EMS/5678)
The Mazda NA was used almost exclusively in the Mazda MX-5 (NA) roadster with longitudinal rear-wheel-drive mounting. This engine received minor regional adaptations-for example, different ECU maps for North American and European markets-and from 1993 the 1.8L 'NB' engine began to supplement it, creating a clear generational divide. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the cylinder block, just below the exhaust manifold (Mazda Workshop Manual 91989-89). The 5th and 6th digits of the VIN typically indicate engine displacement ('B6' for 1.6L). Visually, the NA engine has a distinctive black plastic cam cover with '16 Valve' embossed on it. Critical differentiation from the later 1.8L NB engine: The NA has a single-piece intake manifold and a different distributor/coil setup. The 1.6L NA engine is a non-interference design, unlike many contemporary engines.
The NA engine is renowned for its robustness, with its primary long-term concern being oil consumption in high-mileage examples. Mazda service data indicates this is often linked to worn valve stem seals, while UK DVSA records show very few engine-related MOT failures for well-maintained MX-5s. Infrequent oil changes and aggressive driving can accelerate wear on the camshafts and hydraulic lifters, making adherence to the maintenance schedule critical.
Analysis derived from Mazda technical bulletins (1989-1997) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA NA.
Comprehensive technical documentation and regulatory references
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MAZDA 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
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