The Mazda DHG is a 2,191 cc, inline‑four turbocharged diesel engine produced between 2014 and 2021. It features a dual overhead camshaft (DOHC) design with 16 valves and incorporates Mazda's SKYACTIV — D technology, including a two — stage twin — scroll turbocharger and high 14.0:1 compression ratio. This combination delivers 129 kW (175 PS) and 420 Nm of torque, providing strong, responsive performance.
Fitted to the DJ — generation Mazda6 and some variants of the JDM Maz…

Production years 2014–2021 meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/9012).
The Mazda DHG is a 2,191 cc inline‑four turbocharged diesel engine engineered for mid-size sedans and SUVs (2014-2021). It combines DOHC 16-valve architecture with a two-stage twin-scroll turbocharger to deliver strong, linear torque and refined power delivery. Designed to meet stringent Euro 6 standards, it balances performance with advanced emissions control.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,191 cc | |
Fuel type | Diesel | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Twin-scroll turbocharged | |
Bore × stroke | 86.0 mm × 94.3 mm | |
Power output | 129 kW (175 PS) | |
Torque | 420 Nm @ 2,000 rpm | |
Fuel system | Common rail direct injection (up to 1,800 bar) | |
Emissions standard | Euro 6 | |
Compression ratio | 14.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Two-stage twin-scroll (MHI) | |
Timing system | Chain-driven | |
Oil type | SAE 0W‑30 (ACEA C2/C3) | |
Dry weight | 165 kg |
The Mazda DHG was used across Mazda's DJ platform with transverse mounting. This engine received minor ECU calibration adaptations for different global markets and trim levels, creating no significant interchange limits. All adaptations are documented in OEM technical bulletins.
The DHG's primary reliability consideration is the AdBlue injection system, with elevated incidence of crystallization in vehicles subjected to low annual mileage or frequent short trips. Mazda service data indicates a correlation between driving patterns and AdBlue system faults, while the engine internals and timing chain are generally robust. Maintaining correct driving habits and following preventative service advice is critical for long-term system health.
Analysis derived from Mazda technical bulletins (2014-2021) and general industry repair data. 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 DHG is a technologically advanced and generally robust engine. Its main considerations are the complexity of its emissions systems (AdBlue, DPF, EGR). With proper maintenance, use of correct oil, and a driving pattern that includes regular highway journeys, these engines can achieve high mileages without major issues. The timing chain is very durable.
The most frequent issues relate to its emissions control: AdBlue injector crystallization (especially in low-mileage cars), DPF regeneration problems, and EGR cooler leaks. Low-pressure fuel pump failure is also a known fault. These are well-documented in Mazda service information and are typical for modern Euro 6 diesels.
The DHG was primarily used in the third-generation Mazda6 (DJ chassis, 2014-2021) across various global markets. It was also fitted to the Japanese Domestic Market (JDM) version of the second-generation Mazda CX-5 (KE chassis) from 2017 to 2021, replacing the earlier SH engine in that market.
Yes, but with significant caveats. An ECU remap can yield substantial power and torque gains (up to 40-50 kW). However, this puts immense stress on the emissions systems (DPF, EGR) and can lead to premature failure. Many tuners recommend removing emissions hardware (which is illegal for road use in most regions) for a reliable tune, making it a complex and legally questionable project.
Excellent for its performance. In a Mazda6, expect combined figures of ~5.5 L/100km (51 mpg UK). Highway cruising can drop to ~4.5 L/100km (63 mpg UK), while city driving might be around ~7.0 L/100km (40 mpg UK). Real-world economy is highly dependent on driving style and ensuring the DPF regenerates properly.
Yes. The DHG is an interference engine. If the timing chain were to fail or jump significantly, the pistons would collide with the open valves, causing severe internal engine damage. Fortunately, the chain is extremely durable with proper maintenance.
Mazda specifies SAE 0W-30 engine oil meeting ACEA C2 or C3 (low-ash) standards. Using the correct low-ash oil is absolutely critical to prevent clogging of the Diesel Particulate Filter (DPF). Change intervals should not exceed 15,000 km or 12 months.
Comprehensive technical documentation and regulatory references
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MAZDA Official Site
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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
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