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 Mazda CX-5, the DHG was engineered for drivers seeking a blend of executive saloon refinement, strong overtaking power, and long-distance efficiency. Emissions compliance for its production run was achieved through a sophisticated exhaust aftertreatment system including a Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) with AdBlue, meeting Euro 6 standards.
One documented service concern is potential crystallization of AdBlue (Diesel Exhaust Fluid) in the injector lines or nozzle, particularly in vehicles with low annual mileage or frequent short trips. This issue, referenced in Mazda Service Bulletin A01‑03‑16, can lead to reduced NOx conversion efficiency and trigger warning lights. The system includes a heating element to mitigate this, but preventative maintenance is advised.
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 two-stage turbo provides strong, lag-free torque ideal for highway cruising but requires strict adherence to 15,000 km or 12-month oil change intervals to protect the turbo and emissions systems. Using the specified 0W-30 low-ash oil is critical to prevent DPF clogging. The AdBlue system demands periodic refills and can suffer from crystallization if the vehicle is used for predominantly short trips; Mazda SIB A01-03-16 recommends preventative cleaning for low-mileage vehicles. The chain-driven timing system is generally robust but should be inspected for noise during major services.
Oil Specs: Requires SAE 0W-30 meeting ACEA C2/C3 specification to protect DPF/SCR systems (Mazda Owner's Manual DJ-2014).
Emissions: Euro 6 certification applies to all 2014–2021 models (VCA Type Approval #VCA/EMS/9012).
Power Ratings: Measured under SAE J1349 standards. Output is consistent across model applications (Mazda TIS Doc. DHG-001).
Mazda Technical Information System (TIS): Docs DJ-2014, DHG-001, A01-03-16
VCA Type Approval Database (VCA/EMS/9012)
SAE International: J1349 Engine Power Certification Standards
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.
Locate the engine code stamped on a flat pad on the front of the cylinder block, near the alternator (Mazda TIS DHG-002). The 8th VIN digit typically corresponds to the engine type ('H' for DHG series). The DHG is visually identified by its aluminum valve cover and the prominent AdBlue tank and injector lines near the exhaust manifold. Critical differentiation from the earlier SH engine: DHG features a two-stage turbo and SCR/AdBlue system, while the SH uses a single turbo and EGR-only emissions control. Engine mounts and some ancillary brackets are specific to the vehicle model.
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.
Find answers to most commonly asked questions about MAZDA DHG.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with MAZDA or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
MAZDA Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialMAZDA documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
