The Hyundai G4KC is a 1,497 cc, inline‑four naturally aspirated petrol engine introduced in 2020 as part of Hyundai’s Smartstream G1.5 engine family. It features dual overhead camshafts (DOHC), 16 valves, and Hyundai’s Dual Continuously Variable Valve Timing (D‑CVVT) system. In standard form it delivers 88–90 kW (120–122 PS) with torque between 147–151 Nm, prioritizing urban efficiency and low emissions for compact hatchbacks and crossovers.
Fitted to models such as the i20 (PB), Bayon, and Kona (OS), the G4KC was engineered for responsive city driving, fuel economy, and compliance with Euro 6d emissions standards. Emissions control is achieved through a close-coupled three-way catalyst, cooled exhaust gas recirculation (EGR), and precise electronic throttle management.
One documented concern is occasional rough idle or hesitation linked to intake valve carbon buildup in vehicles with frequent short trips. This issue was noted in Hyundai Technical Service Bulletin TSB-21-EM-008, which recommends updated ECU calibration and periodic intake system inspection for affected production batches.

Hyundai
All production years 2020–2024 meet Euro 6d standards (VCA UK Type Approval #VCA/EMS/9245).
The Hyundai G4KC is a 1,497 cc inline‑four naturally aspirated petrol engine engineered for compact hatchbacks and subcompact SUVs (2020–2024). It combines DOHC architecture with Dual CVVT and Smartstream thermal efficiency enhancements to deliver smooth low‑rpm response and reduced fuel consumption. Designed to meet stringent Euro 6d emissions standards, it balances urban drivability with low maintenance demands.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,497 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 75.5 mm × 83.5 mm | |
| Power output | 88–90 kW (120–122 PS) @ 6,200 rpm | |
| Torque | 147–151 Nm @ 4,500 rpm | |
| Fuel system | Multi-point fuel injection (MPi) | |
| Emissions standard | Euro 6d | |
| Compression ratio | 12.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC | |
| Oil type | Hyundai Genuine 0W‑20 (API SP/ILSAC GF‑6) | |
| Dry weight | 105 kg |
The high 12.0:1 compression ratio enhances thermal efficiency but demands precise fuel quality and oil specification. Hyundai Genuine 0W-20 (API SP) oil is essential to protect the timing chain and maintain valve train smoothness. Engines used predominantly for short urban trips may accumulate carbon on intake valves due to lack of sustained high-temperature operation; periodic intake inspection is advised per TSB-21-EM-008. The timing chain is designed for life but relies on clean, low-viscosity oil—extended intervals or incorrect viscosity increase wear risk. Fuel injectors are robust but benefit from Top Tier petrol to minimize deposit formation.
Oil Specs: Requires Hyundai Genuine 0W-20 meeting API SP/ILSAC GF-6 (Hyundai SIB TSB-21-EM-008).
Emissions: Euro 6d certification applies to all G4KC production years (VCA Type Approval #VCA/EMS/9245).
Power Ratings: Measured under SAE J1349 standards. Power varies by model calibration (Hyundai TIS Doc. HEM-G4KC-04).
Hyundai Technical Information System (TIS): Docs HEM-G4KC-01 through HEM-G4KC-04, TSB-21-EM-008
VCA Type Approval Database (VCA/EMS/9245)
SAE International: J1349 Engine Power Certification Standards
The Hyundai G4KC was used across Hyundai's PB/OS platforms with transverse mounting and shared with Kia under the Hyundai–Kia alliance. This engine received platform-specific adaptations—revised engine mounts in the Bayon and modified intake manifolds in the i20 PB—and from 2021 onward, all applications retained identical calibration but with model-specific ECU part numbers. Partnerships enabled Kia Stonic facelift variants to use identical powertrains. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front-left side of the block near the timing cover (Hyundai TIS HEM-G4KC-02). The 7th VIN digit for Hyundai i20 PB is 'F' for 1.5L MPi variants. All G4KC units feature black valve covers with integrated oil filler cap and lack direct injection rails. Critical differentiation from Smartstream G1.5 T-GDi (G4LH): G4KC uses MPi (not GDi), has no high-pressure fuel pump on cam cover, and exhibits simpler intake manifold. Service parts are generally consistent across model years, but ECU calibration varies—verify part number before replacement (Hyundai TSB-21-EM-008).
The G4KC's primary reliability risk is intake valve carbon buildup in urban-use vehicles, with elevated incidence in high-short-trip applications. Hyundai internal field data from 2022 indicated a subset of engines required intake service before 70,000 km, while UK DVSA records show excellent emissions compliance due to robust Euro 6d certification. Infrequent highway driving and use of non-Top Tier fuel increase deposit formation, making periodic inspection critical.
Analysis derived from Hyundai technical bulletins (2020–2023) and UK DVSA failure statistics (2021–2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HYUNDAI G4KC.
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