The Honda P12A is a 1,247 cc, inline‑three naturally aspirated petrol engine produced between 2003 and 2007. It features a single overhead camshaft (SOHC) design with i-DSI (intelligent Dual & Sequential Ignition), delivering 55 kW (75 PS) and 110 Nm of torque. This compact engine prioritizes fuel efficiency and low emissions for urban mobility.
Fitted exclusively to the second-generation Honda Jazz (GD), the P12A was engineered for responsive, economical city driving. Emissions compliance was achieved through precise dual-spark ignition and a close-coupled catalytic converter, meeting Euro 4 standards across its production run.
One documented concern is potential carbon buildup on spark plugs due to the i-DSI system's dual ignition, noted in Honda Service Bulletin A05-018. This is often linked to extended low-RPM operation and can cause misfires. Honda addressed this with revised spark plug specifications and updated maintenance intervals.
Honda
All production years 2003–2007 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/5681).
The Honda P12A is a 1,247 cc inline‑three naturally aspirated petrol engine engineered for compact hatchbacks (2003-2007). It combines i-DSI dual ignition with port fuel injection to deliver exceptional fuel economy and low emissions. Designed to meet Euro 4 standards, it balances urban efficiency with reliable operation.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,247 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑3, SOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 73.0 mm × 79.0 mm | |
| Power output | 55 kW (75 PS) @ 5,700 rpm | |
| Torque | 110 Nm @ 2,800 rpm | |
| Fuel system | Port fuel injection (PFI) with i-DSI | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | Honda 5W-30 | |
| Dry weight | 85 kg |
The i-DSI system provides excellent fuel economy but requires regular spark plug changes with the correct dual-ground electrode type to prevent misfires. The 10.8:1 compression ratio is compatible with standard RON 95 fuel. The timing chain is generally maintenance-free. The engine’s light weight and compact size contribute significantly to the vehicle’s agility and low running costs. Extended low-speed driving can accelerate carbon buildup on spark plugs.
Oil Specs: Requires Honda 5W-30 specification (Honda Owner's Manual GD2). No 0W-20 variant was specified for this engine.
Emissions: Euro 4 certification applies to all 2003–2007 models (VCA Type Approval #VCA/EMS/5681). No market-specific variations.
Power Ratings: Measured under SAE J1349 standards. Peak output requires RON 95+ fuel (Honda TIS Doc. P12A-003).
Honda Technical Information System (TIS): Docs P12A-001, P12A-002, P12A-003
VCA Type Approval Database (VCA/EMS/5681)
SAE International: J1349 Engine Power Certification Standards
The Honda P12A was used exclusively in Honda's GD platform with transverse mounting. This engine was not licensed to other manufacturers. All applications are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the cylinder block, near the alternator (Honda TIS P12A-004). The 8th VIN digit for GD2 Jazz is 'G'. Visually, the P12A has a black plastic valve cover and two ignition coils per cylinder (total of six coils for three cylinders), which is a hallmark of the i-DSI system. Critical differentiation from other Honda 1.2L engines: The P12A is the only one with i-DSI; other variants use single-spark ignition. ECU and ignition components are not interchangeable.
The P12A's primary reliability risk is related to carbon-fouled spark plugs, with incidence highest in vehicles subjected to frequent short trips or prolonged low-RPM driving. Honda internal service data indicates this is typically due to the nature of the i-DSI system and can be mitigated with correct maintenance. Adherence to the 5W-30 oil specification and 15,000 km service intervals is critical for long-term engine health.
Analysis derived from Honda technical bulletins (2003-2007) and UK DVSA failure statistics (2005-2015). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HONDA P12A.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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