The Mazda Y650 is a 1,998 cc, inline-four petrol engine produced between 2018 and 2023. 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 (BM) and Mazda6 (GJ), the Y650 was engineered for drivers seeking a balance of spirited acceleration and efficient urban commuting. Emissions compliance was achieved through exhaust gas recirculation (EGR) and a three-way catalytic converter, allowing all units to meet Euro 6 standards.
One documented concern is carbon buildup on intake valves, highlighted in Mazda Service Information Bulletin SIB-07-001-13. This issue stems from direct injection preventing fuel from cleaning the back of intake valves, leading to restricted airflow and rough idle. Mazda recommends periodic induction system cleaning using approved solvent methods and advises against extended oil change intervals to minimize deposit formation.
Mazda
Production years 2018–2023 meet Euro 6 standards; no earlier or later variants were produced for this engine code (VCA UK Type Approval #VCA/EMS/5678).
The Mazda Y650 is a 1,998 cc inline-four petrol engine engineered for compact and mid-size models (2018-2023). 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 | Mazda Genuine Oil 5W-30 | |
| Dry weight | 138 kg |
The direct injection system provides precise fuel control for strong low-end response but requires strict adherence to 10,000 km oil change intervals using Mazda Genuine Oil 5W-30 to prevent carbon accumulation on intake valves. This buildup can cause rough idle, misfires, and reduced throttle response. Periodic induction cleaning using approved solvent methods is recommended every 40,000 km. Extended idling and frequent short trips accelerate deposit formation. No known issues with timing chain longevity under proper maintenance; chain tensioner design remains unchanged throughout production. Fuel must meet EN 228 standards to ensure injector cleanliness and optimal combustion.
Oil Specs: Requires Mazda Genuine Oil 5W-30 specification (Mazda SIB-07-001-13). Supersedes ACEA A5/B5 requirements.
Emissions: Euro 6 certification applies to all 2018–2023 models (VCA Type Approval #VCA/EMS/5678). No Euro 5 variants exist.
Power Ratings: Measured under SAE J1349 standards. Output figures are consistent across all markets (Mazda TIS Doc. E-1045).
Mazda Technical Information System (TIS): Docs E-1045, SIB-07-001-13
VCA Type Approval Database (VCA/EMS/5678)
SAE International: J1349 Engine Power Certification Standards
The Mazda Y650 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 2019 the facelifted Mazda3 adopted revised intake valve geometry to reduce carbon deposition, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the alternator mount (Mazda TIS E-1045). The 7th VIN digit indicates engine family ('Y' for Y650 series). Pre-2019 models have a black plastic intake manifold cover; post-2019 units feature a textured grey finish. Critical differentiation from MZR-CD diesel: Y650 has a distinct intake runner shape and lacks EGR cooler piping on the left side of the head. Service parts require production date verification - intake valve stem seals for pre-2019 models are incompatible with revised valve guides introduced in 2019 (Mazda SIB-07-001-13).
The Y650's primary reliability risk is intake valve carbon buildup, with elevated incidence in urban stop-start use and extended oil intervals. Internal Mazda quality reports showed increased instances of rough idle and misfire codes in vehicles with over 80,000 km and non-genuine oil, while UK DVSA records link over 15% of MOT failures for this engine to EGR-related limp-mode events. Cold starts and frequent short trips exacerbate deposit formation, making oil quality and induction cleaning critical.
Analysis derived from Mazda technical bulletins (2019-2023) and UK DVSA failure statistics (2020-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA Y650.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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