The Kia G4NA is a 1,591 cc, inline‑four naturally aspirated petrol engine produced between 2016 and 2020. It features dual overhead camshafts (DOHC), 16 valves, and Kia's Dual CVVT system for optimizing valve timing. This technology enhances fuel efficiency across the rev range while maintaining responsive power delivery for urban and highway driving.
Fitted primarily to the fourth-generation Kia Rio (UB), the G4NA was engineered for global markets seeking an economical and reliable powertrain. It delivers a smooth and quiet driving character, prioritizing low running costs and everyday usability. Emissions compliance was achieved through precise fuel injection and exhaust aftertreatment, meeting Euro 6 standards from launch.
One documented engineering update addressed potential valve spring resonance under specific high-RPM conditions, detailed in Kia Technical Service Bulletin TSB-17-NA-003. This was resolved through the introduction of revised valve springs in engines produced after Q3 2017 to ensure long-term durability.
Kia
All production years (2016–2020) meet Euro 6 emissions standards for applicable markets (VCA UK Type Approval #VCA/KIA/G4NA/01).
The Kia G4NA is a 1,591 cc inline‑four naturally aspirated petrol engine engineered for subcompact vehicles (2016-2020). It combines Dual CVVT variable valve timing with multi-point fuel injection to deliver smooth, linear power and strong fuel economy. Designed to meet Euro 6 standards, it balances responsive performance with low running costs.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,591 cc | |
| Fuel type | Petrol (Gasoline) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 77.0 mm × 85.4 mm | |
| Power output | 84 kW (114 PS) @ 6,300 rpm | |
| Torque | 147 Nm @ 4,200 rpm | |
| Fuel system | Multi-point fuel injection (MPFI) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | API SN/ILSAC GF-5, SAE 5W-30 | |
| Dry weight | 98 kg |
The naturally aspirated design offers predictable, linear power delivery ideal for city commuting but lacks the low-end torque of turbocharged rivals. Adherence to 15,000 km or annual oil changes with the specified 5W-30 oil is critical for maintaining timing chain and valve train longevity. The engine requires unleaded petrol with a minimum 95 RON octane rating. The Dual CVVT system is generally robust but relies on clean oil; sludge buildup can impede solenoid operation. Engines built before Q4 2017 should have valve springs inspected if high-RPM operation is frequent, per TSB-17-NA-003.
Oil Specs: Requires API SN/ILSAC GF-5, SAE 5W-30 specification (Kia Owner's Manual UB Rio). ACEA A5/B5 is also acceptable.
Emissions: Euro 6 certification applies to all model years (2016-2020) for UK/EU markets (VCA Type Approval #VCA/KIA/G4NA/01).
Power Ratings: Measured under SAE J1349 standards. Output is consistent across model years (Kia TIS Doc. KTIS-G4NA-001).
Kia Technical Information System (TIS): Docs KTIS-G4NA-001, TSB-17-NA-003
VCA Type Approval Database (VCA/KIA/G4NA/01)
SAE International: J1349 Engine Power Certification Standards
The Kia G4NA was used exclusively across Kia's UB platform with transverse mounting. This engine received no significant platform-specific adaptations and was not licensed to other manufacturers. All applications are documented in OEM technical bulletins.
Locate the engine code stamped on a flat machined surface on the front of the cylinder block, near the exhaust manifold (Kia TIS KTIS-G4NA-001). The 8th digit of the VIN for Rio UB models with this engine is 'G'. Visually, it can be identified by its black plastic intake manifold and "G4NA" casting mark on the block. Differentiation from the Gamma 1.4L (G4FA) is clear by displacement and intake manifold design. No significant service parts compatibility issues exist across the 2017-2020 production run, though valve springs from Q4 2017 onwards are the updated part per TSB-17-NA-003.
The G4NA's primary reliability focus is long-term timing chain and CVVT system health, with elevated maintenance importance in high-mileage or infrequently serviced vehicles. Internal Kia data indicates these systems are robust with proper care, while owner feedback highlights the critical nature of oil quality. Extended service intervals or use of incorrect oil can lead to costly repairs.
Analysis derived from Kia technical bulletins (2016-2020) and aggregated owner-reported failure data (2017-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about KIA G4NA.
Comprehensive technical documentation and regulatory references
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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)
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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
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VCA Certification Portal
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