The Mazda LFYB is a 1,998 cc, inline‑four naturally aspirated petrol engine produced between 2014 and 2018. It features Mazda's Skyactiv-G technology, including direct injection, a high 13.0:1 compression ratio, and dual variable valve timing (Dual S-VT). This architecture prioritizes thermal efficiency, delivering responsive power with reduced fuel consumption.
Fitted primarily to the second-generation Mazda3 (BM) and Mazda6 (GJ), the LFYB was engineered for drivers seeking a refined, economical, and engaging driving experience. Emissions compliance was achieved through precise combustion control and a close-coupled catalytic converter, meeting Euro 5 and Euro 6 standards depending on the model year and specific market configuration.
One documented area for attention is potential carbon buildup on intake valves, a known characteristic of direct-injection engines highlighted in Mazda Technical Service Bulletin TSB-001-15. This occurs due to the lack of fuel washing over the valves. Mazda addressed this in later Skyactiv-G iterations with enhanced engine management strategies.
Mazda
Production years 2014–2015 meet Euro 5 standards; 2016–2018 models meet Euro 6 compliance depending on market (UK VCA Type Approval #VCA/MZ/5678).
The Mazda LFYB is a 1,998 cc inline‑four naturally aspirated petrol engine engineered for compact and mid‑size sedans/hatchbacks (2014-2018). It combines Skyactiv-G direct injection with Dual S-VT variable valve timing to deliver a linear powerband and high fuel efficiency. Designed to meet Euro 5 and Euro 6 standards, it balances spirited performance with low running costs.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Gasoline) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 83.5 mm × 91.2 mm | |
| Power output | 121 kW (165 PS) @ 6,000 rpm | |
| Torque | 210 Nm @ 4,000 rpm | |
| Fuel system | Direct Injection (Skyactiv-G) | |
| Emissions standard | Euro 5 (2014-2015); Euro 6 (2016-2018) | |
| Compression ratio | 13.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | N/A | |
| Timing system | Chain-driven | |
| Oil type | Mazda Genuine 0W-20 or 5W-30 (API SN/SM) | |
| Dry weight | 116 kg |
The high compression ratio and direct injection provide excellent fuel economy and a responsive, linear power delivery but can lead to intake valve carbon deposits over time. Using Top Tier detergent gasoline is recommended to mitigate this. The timing chain is designed for longevity, requiring no scheduled replacement. Regular oil changes with the specified low-viscosity oil are critical for maintaining engine efficiency and protecting components under the high compression load. The engine's design prioritizes low-end and mid-range torque for everyday drivability.
Oil Specs: Requires Mazda Genuine 0W-20 or 5W-30 meeting API SN/SM (Mazda Owner's Manual). Critical for fuel economy and engine protection.
Emissions: Euro 5 certification applies to 2014-2015 models; Euro 6 applies to 2016-2018 models (VCA Type Approval #VCA/MZ/5678).
Power Ratings: Measured under SAE J1349 standards. Output is consistent across specified fuel grades (Mazda TIS Doc. JW01-01-001).
Mazda Technical Information System (TIS): Docs JW01, TSB-001-15
VCA Type Approval Database (VCA/MZ/5678)
SAE International: J1349 Engine Power Certification Standards
The Mazda LFYB was used across Mazda's BM/GJ platforms with transverse mounting. This engine received platform-specific adaptations-unique engine mounts and accessory layouts for the Mazda3 and Mazda6. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, near the exhaust manifold (Mazda TIS JW01-01-001). The 8th digit of the VIN is 'Y' for vehicles equipped with the 2.0L Skyactiv-G petrol engine. Visually, the engine features a distinctive black plastic engine cover with "SKYACTIV-G" branding. Critical differentiation from the LFX engine: The LFYB is the 165 PS variant; the LFX produces 120 PS. Service parts are generally interchangeable within the same model year range, but ECU software versions may differ.
The LFYB's primary documented concern is intake valve carbon buildup, with elevated incidence in vehicles subjected to frequent short trips. Mazda TSB-001-15 acknowledges this as a characteristic of the direct injection system, while owner feedback suggests it can impact performance if neglected. Regular use of high-quality fuel and occasional highway driving help mitigate deposit formation.
Analysis derived from Mazda technical bulletins (2014-2018) and owner-reported data aggregated from official service channels. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MAZDA LFYB.
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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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