The Mitsubishi G15B is a 1,468 cc, inline‑four naturally aspirated petrol engine produced between 1983 and 1991. It features a single overhead camshaft (SOHC), 8 valves, and a carburettor or throttle — body fuel injection system depending on market and year. In standard form it delivered 55–63 kW (75–86 PS) with torque of 110–120 Nm, engineered for economical urban driving and basic reliability.
Fitted to entry — level models such as the Mirage (C10/C20), Lancer (CA), and…
Production years 1983–1991 meet no formal EU emissions standard (pre-Euro 1); Japanese domestic models complied with 1983–1991 JIS emission regulations (Mitsubishi ETK Doc. ME-G15B-01).
The Mitsubishi G15B is a 1,468 cc inline‑four naturally aspirated petrol engine engineered for compact hatchbacks and sedans (1983–1991). It combines SOHC 8-valve architecture with carburettor or throttle-body injection to deliver basic urban performance and serviceability. Designed before formal Euro standards, it relies on rudimentary emissions controls and prioritizes mechanical simplicity.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,468 cc | |
Fuel type | Petrol (Unleaded) | |
Configuration | Inline‑4, SOHC, 8‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 75.5 mm × 82.0 mm | |
Power output | 55–63 kW (75–86 PS) @ 5,500 rpm | |
Torque | 110–120 Nm @ 3,500 rpm | |
Fuel system | Carburettor or throttle-body injection (TBI) | |
Emissions standard | Pre-Euro (JIS 1983–1991 compliant) | |
Compression ratio | 9.2:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt‑driven SOHC | |
Oil type | API SF/SG, SAE 10W‑30 | |
Dry weight | 92 kg |
The Mitsubishi G15B was used across Mitsubishi's C-platform with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Mirage and modified cooling in the Lancer—and from 1988 the distributor drive gear was revised, creating minor parts incompatibility. All adaptations are documented in OEM technical bulletins.
The G15B's primary reliability risk is distributor drive gear wear in early builds, with elevated incidence in high-ambient-temperature climates or vehicles with delayed oil changes. Mitsubishi internal field data from 1988 indicated distributor faults in ~10% of pre-1988 engines before 100,000 km, while period service records show low emissions failure rates due to simple oxidation catalyst design. Thermal stress and oil degradation make lubrication quality and timing belt discipline critical.
Analysis derived from Mitsubishi technical bulletins (1986–1990) and Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) service records (1985–1992). 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 G15B is generally reliable with proper maintenance. Early models (1983–1987) had distributor drive gear concerns in hot climates, largely resolved by 1988 updates. The belt-driven SOHC design is simple but requires strict timing belt and oil change adherence. With correct servicing, these engines commonly exceed 200,000 km in urban use.
Top issues include distributor drive gear wear (pre-1988), timing belt failure due to missed replacement, carburettor varnish from ethanol fuel, and exhaust manifold gasket leaks. Most are preventable with regular oil changes, timely belt service, and using OEM parts. Mitsubishi issued TSB-ENG-1987-03 addressing distributor durability.
The 1.5L G15B powered the Mirage/Colt (1983–1991), Lancer (1983–1987), Tredia (1983–1987), and Cordia (1983–1987). All are transverse-mounted, front-wheel-drive applications with SOHC 8-valve architecture. No cross-manufacturer usage is documented.
Limited tuning potential due to SOHC 8-valve design and modest displacement. Carburettor jetting or TBI recalibration can yield minimal gains (~3–5 kW). Forced induction is impractical without internal upgrades. Most owners focus on reliability over power; significant tuning is not cost-effective.
In a 1986 Mirage 1.5, typical consumption is ~7.5 L/100km (city) and ~5.8 L/100km (highway), or about 44 mpg UK combined. Real-world figures range from 40–48 mpg (UK) depending on driving style and vehicle weight. It meets pre-Euro standards with EN 228 fuel.
Yes. The G15B is an interference engine. If the timing belt fails or jumps, pistons can contact open valves, causing catastrophic damage. This is why the 80,000 km or 4-year timing belt replacement is critical—never delay this service.
Mitsubishi specifies API SF or SG grade petrol oil in SAE 10W‑30 viscosity. Use a quality mineral or semi-synthetic blend and change every 10,000 km or 12 months. Correct oil is essential for camshaft and distributor drive lubrication.
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