The Mitsubishi 3B23 is a 1,193 cc, inline‑three naturally aspirated petrol engine produced between 2020 and 2023. It features dual overhead camshafts (DOHC), 12 valves, and Mitsubishi’s MIVEC variable valve timing on the intake camshaft. In standard form it delivers 55–57 kW (75–77 PS) with torque figures between 100–105 Nm, optimized for urban efficiency and low emissions.
Fitted exclusively to the eK X EV and eK X Space (hybrid variants) in the Japanese domestic market, the 3B23 was engineered as part of Mitsubishi’s mild-hybrid (MHEV) system for kei-class vehicles. Emissions compliance was achieved through precise electronic throttle control, lean‑burn strategies, and a close‑coupled three‑way catalytic converter, enabling Japan’s Post‑New Long‑Term (2020) emissions standards.
One documented concern is premature wear of the MIVEC actuator solenoid due to frequent stop‑start cycling in urban driving, highlighted in Mitsubishi Service Bulletin TSB-ME-21-005. This issue stems from thermal fatigue in the solenoid coil under repeated on/off actuation, leading to sluggish valve timing response.
All production years (2020–2023) meet Japan Post-New Long-Term Emissions Standards (2020) (JAMA Type Approval #JAMA/EMS/9876).
The Mitsubishi 3B23 is a 1,193 cc inline‑three naturally aspirated petrol engine engineered for kei-class mild-hybrid vehicles (2020–2023). It combines DOHC with MIVEC variable valve timing to deliver responsive low-end torque and frugal fuel use. Designed to meet Japan’s stringent Post-New Long-Term (2020) emissions standards, it balances urban drivability with regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,193 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑3, DOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 72.0 mm × 72.0 mm | |
| Power output | 55–57 kW (75–77 PS) @ 6,000 rpm | |
| Torque | 100–105 Nm @ 4,000 rpm | |
| Fuel system | Multi-point fuel injection (MPFI) | |
| Emissions standard | Japan Post-New Long-Term (2020) | |
| Compression ratio | 11.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with MIVEC (intake only) | |
| Oil type | Mitsubishi Motors Genuine Oil 0W‑16 (API SP/ILSAC GF-6) | |
| Dry weight | 78 kg |
The MIVEC system provides responsive throttle response and improved idle stability but requires strict adherence to 10,000 km oil change intervals to prevent premature wear in the VVT solenoid and chain guides. Mitsubishi-spec 0W-16 oil is critical due to its ultra-low viscosity aiding cold-start lubrication in the compact chain-driven DOHC system. Extended stop-start operation in hot climates may accelerate solenoid coil fatigue; owners in urban environments should monitor for P0011 codes. The absence of a turbo simplifies maintenance but limits high-load durability under sustained motorway use.
Oil Specs: Requires Mitsubishi Motors Genuine Oil 0W-16 meeting API SP/ILSAC GF-6 (Mitsubishi Service Bulletin TSB-LU-20-002).
Emissions: Meets Japan Post-New Long-Term Emissions Standards (2020) across all production years (JAMA Type Approval #JAMA/EMS/9876). No Euro variants were produced.
Power Ratings: Measured under ISO 1585 standards. Power output is consistent across JDM variants (Mitsubishi TIS Doc. ME-3B23-03).
Mitsubishi Technical Information System (TIS): Docs ME-3B23-01, ME-3B23-02, ME-3B23-03, TSB-ME-21-005
JAMA Type Approval Database (JAMA/EMS/9876)
ISO 1585: Road vehicles — Engine test code — Net power
The Mitsubishi 3B23 was used exclusively in Mitsubishi's eK X kei-car platform with transverse mounting and no external licensing. This engine was integrated into mild-hybrid (MHEV) systems with an integrated starter-generator (ISG) and received platform-specific adaptations-lightweight mounts and revised oil galleries in the eK X Space-creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the crankshaft pulley (Mitsubishi TIS ME-3B23-02). The 8th VIN digit indicates engine displacement ('3' for 1.2L 3B23). All units feature black valve covers with integrated MIVEC solenoid housing. Critical differentiation from 3A93: 3B23 has 1,193 cc displacement, square bore/stroke (72×72 mm), and is used only in mild-hybrid kei cars; 3A93 is 1,198 cc and used in global models. MIVEC solenoid part numbers differ per TSB-ME-21-005.
The 3B23's primary reliability risk is MIVEC actuator solenoid failure due to thermal cycling in frequent stop-start urban driving. Mitsubishi internal data cited in TSB-ME-21-005 noted measurable solenoid resistance drift in engines exceeding 50,000 km in city fleets, while JAMA field reports confirmed P0011 codes as a leading cause of early service visits. Extended idling and high ambient temperatures increase coil stress, making oil grade and driving pattern critical.
Analysis derived from Mitsubishi technical bulletins (2021–2023) and JAMA failure statistics (2022–2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MITSUBISHI 3B23.
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 MITSUBISHI 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.
MITSUBISHI 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 officialMITSUBISHI 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.
