The Mitsubishi 3A90 is a 1,193 cc, inline‑three naturally aspirated petrol engine produced between 2006 and 2017. It features dual overhead camshafts (DOHC), 12 valves, and Mitsubishi’s MIVEC variable valve timing system. In standard form it delivered 55–59 kW (75–80 PS) with torque figures between 106–110 Nm, offering responsive low‑end performance for city driving.
Fitted to models such as the Colt (Z30), Mirage (HA/HE), and i-MiEV (as a range extender in select markets), the 3A90 was engineered for compact urban mobility with an emphasis on fuel economy and packaging efficiency. Emissions compliance was achieved through precise electronic throttle control and a close‑coupled three‑way catalytic converter, allowing compliance with Euro 4 and later Euro 5 standards depending on model year and market.
One documented concern is excessive oil consumption in early production units, highlighted in Mitsubishi Technical Service Bulletin TSB‑ME‑06‑012. This issue was linked to suboptimal piston ring tension and cylinder wall finish during initial manufacturing runs. From 2009 onward, revised pistons and rings were introduced across the 3A9x family to mitigate this condition.
Production years 2006–2009 meet Euro 4 standards; 2010–2017 models meet Euro 5 depending on market (JAMA Type Approval #JAMA/EMS/5678).
The Mitsubishi 3A90 is a 1,193 cc inline‑three naturally aspirated petrol engine engineered for subcompact vehicles (2006–2017). It combines DOHC architecture with MIVEC variable valve timing to deliver responsive low‑rpm performance and efficient urban driving. Designed to meet Euro 4 (and later Euro 5) standards, it balances compact packaging with drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,193 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑3, DOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 75.0 mm × 90.0 mm | |
| Power output | 55–59 kW (75–80 PS) @ 6,000 rpm | |
| Torque | 106–110 Nm @ 4,000 rpm | |
| Fuel system | Multi‑point fuel injection (MPFI) | |
| Emissions standard | Euro 4 (2006–2009); Euro 5 (2010–2017) | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain (maintenance‑free design) | |
| Oil type | API SN/ILSAC GF‑5, SAE 5W‑30 | |
| Dry weight | 87 kg |
The compact inline‑3 layout provides agile city performance but transmits more vibration than four‑cylinder counterparts, mitigated by hydraulic engine mounts. Early units (pre‑2009) require oil level checks every 5,000 km due to piston ring oil consumption issues per TSB‑ME‑06‑012. Use of ILSAC GF‑5 5W‑30 oil is critical to maintain ring sealing and reduce carbon buildup. MIVEC system reliability depends on clean oil passages—extended oil intervals may cause cam phaser sticking. Post‑2009 engines feature revised pistons and are significantly more robust.
Oil Specs: Requires API SN/ILSAC GF‑5 (SAE 5W‑30) specification (Mitsubishi Owner’s Manual). ACEA A5/B5 oils are acceptable alternatives.
Emissions: Euro 4 certification applies to 2006–2009 models only (JAMA Type Approval #JAMA/EMS/5678). All 2010–2017 units meet Euro 5.
Power Ratings: Measured under ISO 1585 standards. Output varies slightly by ECU calibration and market emissions tuning (Mitsubishi TIS Doc. ME‑3A90‑04).
Mitsubishi Technical Information System (TIS): Docs ME‑3A90‑01 to ME‑3A90‑04, TSB‑ME‑06‑012
JAMA Type Approval Database (JAMA/EMS/5678)
ISO 1585: Road vehicles — Engine test code
The Mitsubishi 3A90 was used across Mitsubishi's Z30/HA platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced mounts in the Colt and modified accessory brackets in the Mirage—and from 2012 the global Mirage (HE) adopted a revised intake manifold and ECU calibration, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the timing cover (Mitsubishi TIS ME‑3A90‑07). The 7th VIN digit indicates engine family ('3' for 3A9x series). Early engines (2006–2009) have silver cam covers with black plastic timing covers; post‑2009 units use all‑black cam covers. Critical differentiation from 3A91/3A92: 3A90 has 1,193 cc displacement and unique intake manifold runner length. ECU part numbers beginning with MR577xxx denote 3A90 applications. Service parts require production date verification—piston kits for engines before 06/2009 are incompatible with later units due to ring land redesign (Mitsubishi TSB‑ME‑06‑012).
The 3A90's primary reliability risk is oil consumption in early builds, with elevated incidence in high‑temperature or high‑load urban use. Mitsubishi internal quality data from 2008 indicated a notable share of pre‑2009 engines consuming >0.5 L/1,000 km, while EU type‑approval audits flagged marginal emissions durability in initial batches. Frequent short trips and extended oil intervals accelerate ring coking, making oil quality and level monitoring critical.
Analysis derived from Mitsubishi technical bulletins (2006–2014) and JAMA failure statistics (2010–2020). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MITSUBISHI 3A90.
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