The Mazda S5Y6 is a 1,998 cc, inline — four petrol engine produced between 2015 and 2018. It features direct fuel injection, variable valve timing (VVT), and a high compression ratio of 13.0:1, delivering responsive performance and improved thermal efficiency. The engine's Atkinson — cycle — inspired operation enables better fuel economy during light — load cruising without compromising mid — range torque for everyday drivability.
Fitted to models such as the Mazda3 (B…
Mazda
Production years 2015–2018 meet Euro 6 standards; no earlier or later variants were produced for this engine code .
The Mazda S5Y6 is a 1,998 cc inline-four petrol engine engineered for compact and mid-size models (2015-2018). It combines direct fuel injection with continuously variable valve timing to deliver responsive power delivery and improved thermal efficiency. Designed to meet Euro 6 standards, it balances everyday performance with economy.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,998 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 87.5 mm × 83.1 mm | |
Power output | 110 kW (150 PS) | |
Torque | 200 Nm @ 4,000 rpm | |
Fuel system | Multi-point direct injection (GDI) | |
Emissions standard | Euro 6 | |
Compression ratio | 13.0:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Chain | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 138 kg |
The Mazda S5Y6 was used across Mazda's B-series/G-series platforms with transverse mounting and no licensed external usage. This engine received platform-specific adaptations-revised ECU calibration in the Mazda3 and modified intake manifold routing in the Mazda6-and from 2016 the facelifted Mazda3 adopted revised intake valve geometry to reduce carbon deposition, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. 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 S5Y6 delivers smooth power and good efficiency, but early models developed significant intake valve carbon buildup, especially with extended oil changes or non-genuine oil. Later revisions (post-2016) included redesigned valve stem seals to mitigate this. With strict maintenance using Mazda Genuine Oil 5W-30 and periodic induction cleaning, these engines can be very reliable beyond 150,000 km.
The biggest issues are intake valve carbon buildup causing rough idle and misfires, EGR valve sticking, and aging coil packs leading to intermittent misfires. Oil leaks from camshaft seals also occur with age. These are well-documented in Mazda service bulletins, particularly SIB-07-001-13 for carbon management.
The S5Y6 was used exclusively in the Mazda3 (BM generation, 2015–2018) and Mazda6 (GJ generation, 2015–2018). It powered the 2.0L Sport and 2.0L Touring trims in both models. No other Mazda or partner vehicles used this specific engine variant.
Aftermarket ECU tuning is common on the S5Y6 platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
Very good for its class. In a Mazda3 or Mazda6, typical consumption is ~7.5 L/100km (city) and ~5.5 L/100km (highway), or about 48 mpg UK combined. Real-world figures depend on driving style but expect 45–52 mpg (UK) on mixed roads for a healthy unit with clean intake valves and proper maintenance.
Yes. The S5Y6 is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. Regular inspection of chain tensioner condition and adherence to maintenance schedules are essential to prevent catastrophic failure.
Mazda specifies Mazda Genuine Oil 5W-30 meeting API SN or ILSAC GF-5 standards. Always use full synthetic oil designed for GDI engines and change it at 10,000 km intervals to minimize carbon deposit formation and protect valve train components.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
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.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.