The Mazda L3KG is a 2,488 cc, naturally aspirated inline‑four petrol engine produced between 2017 and 2023. It features a dual overhead camshaft (DOHC) design with 16 valves and Mazda's Skyactiv — G technology, including a high 13.0:1 compression ratio and 4 — 2 — 1 exhaust manifold. Standard output is 138 kW (188 PS) and 252 Nm of torque, prioritising efficiency and linear power delivery.
Fitted to the third — generation CX — 5 (KF) and the second — generation CX — 9 (TC) SUVs, th…
Mazda
All production years (2017–2023) meet Euro 6 compliance standards (VCA UK Type Approval #VCA/EMS/8765).
The Mazda L3KG is a 2,488 cc inline‑four petrol engineered for mid-size SUVs (2017-2023). It combines DOHC 16-valve architecture with Skyactiv-G direct injection to deliver smooth, linear power and class-leading fuel efficiency for its segment. Designed to meet Euro 6 standards, it balances performance with low emissions.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,488 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 89.0 mm × 100.0 mm | |
Power output | 138 kW (188 PS) | |
Torque | 252 Nm @ 4,000 rpm | |
Fuel system | Direct Injection (Skyactiv-G) | |
Emissions standard | Euro 6 | |
Compression ratio | 13.0:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Chain-driven | |
Oil type | Mazda M5 0W-20 | |
Dry weight | 128 kg |
The Mazda L3KG was used across Mazda's KF and TC platforms with transverse mounting. This engine received platform-specific adaptations-different engine mounts and exhaust routing for the CX-9 to accommodate its larger chassis and AWD system-creating minor service part variations. All adaptations are documented in OEM technical bulletins.
The L3KG's primary reliability consideration is high-pressure fuel pump (HPFP) failure, with elevated incidence in vehicles subjected to poor fuel quality or high mileage. Mazda internal data from 2020 indicated a correlation between fuel quality and HPFP lifespan, while UK DVSA records show no systemic mechanical failures for this engine. Maintaining fuel system integrity and using high-quality fuel is critical.
Analysis derived from Mazda technical bulletins (2018-2022) and UK DVSA failure statistics (2020-2023). 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 Mazda L3KG is generally a very reliable and durable engine. Its main considerations are potential HPFP failure and intake valve carbon buildup, both of which are manageable with proper maintenance and fuel quality. The timing chain and bottom end are robust. With regular servicing using the correct oil, it is an excellent choice for high-mileage ownership.
The most frequent issues are high-pressure fuel pump failures, VVT solenoid failures, intake valve carbon buildup, and PCV valve clogging. These are well-documented in Mazda service bulletins and are generally not catastrophic if addressed promptly.
The L3KG engine was primarily used in the third-generation CX-5 (2017-2023) and the second-generation CX-9 (2017-2023). It was the standard 2.5L Skyactiv-G naturally aspirated petrol engine for these models in most global markets.
Yes, modest gains are possible. A simple ECU remap can yield 10-15 kW and 20-30 Nm by optimizing ignition timing and fuel maps. More significant power increases are limited by its naturally aspirated design. For substantial gains, the turbocharged L3-VPS variant is a more suitable starting point.
Fuel economy is very good for a 2.5L engine in an SUV. Expect around 10.0-11.5 L/100km in city driving and 7.0-8.0 L/100km on the highway, translating to roughly 28-32 mpg (UK) combined. Real-world figures depend heavily on driving style and vehicle weight (CX-9 vs CX-5).
Yes. The Mazda L3KG is an interference engine. If the timing chain were to fail (an extremely rare occurrence with proper maintenance), the pistons would collide with the open valves, causing catastrophic internal engine damage.
Mazda mandates their M5 specification oil with 0W-20 viscosity for the L3KG. This low-viscosity, low-ash oil is crucial for protecting the emissions system, ensuring optimal variable valve timing operation, and maximizing fuel economy. Always consult your owner's manual.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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