The Mazda K8Y1 is a 2,488 cc, inline‑four turbocharged petrol engine produced between 2020 and 2025. It features dual overhead camshafts (DOHC), 16 valves, direct fuel injection (GDI), and a twin-scroll turbocharger. In standard form it delivers 170 kW (231 PS) at 5,000 rpm and 420 Nm of torque at 2,000 rpm, providing strong low-end response and refined highway performance.
Fitted to models such as the Mazda CX-5 (KF), CX-60 (GJ), and Mazda6 (GJ) in select markets, the K8Y1 was engineered for drivers seeking a balance of performance, refinement, and compliance with modern emissions standards. Emissions compliance was achieved through a combination of gasoline particulate filter (GPF), cooled exhaust gas recirculation (EGR), and precise GDI control, enabling adherence to Euro 6d standards across all production years.
One documented concern is carbon buildup on intake valves due to the absence of port fuel injection, which can lead to rough idle and reduced efficiency over time. This issue, highlighted in Mazda Service Bulletin MZ-SB-21-008, is common to all direct-injection petrol engines but is mitigated in the K8Y1 by revised EGR routing and enhanced PCV flow from 2022 onward.
Mazda
All production years (2020–2025) meet Euro 6d standards (VCA UK Type Approval #VCA/EMS/9876).
The Mazda K8Y1 is a 2,488 cc inline‑four turbocharged petrol engine engineered for midsize SUVs and sedans (2020–2025). It combines direct injection with a twin-scroll turbocharger to deliver strong low-end torque and smooth power delivery. Designed to meet Euro 6d emissions standards, it balances performance with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,488 cc | |
| Fuel type | Petrol (Unleaded, min. 95 RON) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged (twin-scroll) | |
| Bore × stroke | 87.5 mm × 103.0 mm | |
| Power output | 170 kW (231 PS) @ 5,000 rpm | |
| Torque | 420 Nm @ 2,000 rpm | |
| Fuel system | Gasoline direct injection (GDI), up to 350 bar | |
| Emissions standard | Euro 6d | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled with dual circuits | |
| Turbocharger | Twin-scroll IHI turbocharger with electronic wastegate | |
| Timing system | Chain-driven DOHC with hydraulic tensioner | |
| Oil type | Mazda M5 0W‑20 (API SP/ILSAC GF-6) | |
| Dry weight | 165 kg |
The twin-scroll turbo provides immediate torque from 2,000 rpm but requires consistent use of 95 RON (or higher) fuel to prevent knock and maintain calibration. Mazda M5 0W-20 oil is essential for variable valve timing actuator function and turbo bearing longevity. Direct injection leads to intake valve coking over time; while not severe in early years, periodic walnut blasting or intake cleaning after 80,000 km is recommended. The GPF regenerates passively during normal driving but may require active cycles if primarily used for short trips. Revised EGR routing from 2022 reduces carbon accumulation per Mazda SIB MZ-SB-21-008.
Oil Specs: Requires Mazda M5 0W-20 specification (Mazda Owner’s Manual GJ/KF). Equivalent to API SP/ILSAC GF-6 with Mazda-specific additives.
Emissions: Euro 6d certification applies to all K8Y1 production years (2020–2025) (VCA Type Approval #VCA/EMS/9876).
Power Ratings: Measured under ISO 1585 standards. Power output assumes 95 RON fuel (Mazda TIS Doc. TIS-MZ-K8Y1-01).
Mazda Technical Information System (TIS): Docs TIS-MZ-K8Y1-01, MZ-SB-21-008
VCA Type Approval Database (VCA/EMS/9876)
ISO 1585: Road vehicles — Engine test code
The Mazda K8Y1 was used across Mazda's GJ and KF platforms with longitudinal mounting in rear-wheel-drive-based architectures and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts in the CX-60 GJ for mild-hybrid integration and revised cooling in the CX-5 KF—and from 2022 the Mazda6 GJ adopted a slightly detuned variant for fleet emissions calibration, creating minor ECU interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the left side of the cylinder block near the oil filter housing (Mazda TIS TIS-MZ-K8Y1-01). The 7th VIN digit is 'K' for K8Y1-equipped vehicles. All units feature a black plastic valve cover with 'SKYACTIV-G 2.5T' branding. Critical differentiation from naturally aspirated PY-VPS: K8Y1 uses direct injection, twin-scroll turbo, and a gasoline particulate filter (GPF). ECU part numbers beginning with GY81-18-xxx indicate K8Y1; PY-VPS uses GY71-18-xxx. Service parts require model-year verification—turbochargers and exhaust manifolds differ between CX-5 and CX-60 due to packaging and hybrid system integration (Mazda SIB MZ-SB-22-011).
The K8Y1's primary reliability risk is intake valve carbon fouling due to direct injection, with elevated incidence in short-trip urban use. Mazda internal data from 2023 indicated a moderate rate of idle instability complaints in vehicles exceeding 80,000 km without intake service, while UK DVSA MOT records show excellent emissions compliance thanks to robust GPF and EGR systems. Frequent cold starts without sustained load increase deposit accumulation, making periodic cleaning critical.
Analysis derived from Mazda technical bulletins (2020–2025) and UK DVSA failure statistics (2020–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA K8Y1.
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