The Hyundai G6AT is a 2,656 cc, V6 naturally aspirated petrol engine produced between 2002 and 2006. It features a dual overhead camshaft (DOHC), 24‑valve configuration and sequential multi‑point fuel injection (SFI), delivering 125 kW (170 PS) and 245 Nm of torque. Its design prioritised smooth power delivery and refinement for mid‑size sedans and SUVs.
Fitted to models such as the Sonata (NF), Santa Fe (SM), and Trajet (FO), the G6AT was engineered for drivers seeking V…
All production years (2002–2006) meet Euro 3 emissions standards (VCA UK Type Approval #VCA/EMS/7123).
The Hyundai G6AT is a 2,656 cc V6 naturally aspirated petrol engine engineered for mid-size models (2002–2006). It combines DOHC 24‑valve architecture with sequential multi-point fuel injection to deliver smooth mid-range power and refined idle quality. Designed to meet Euro 3 emissions standards, it balances performance with drivability in both urban and highway conditions.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,656 cc | |
Fuel type | Petrol (Unleaded) | |
Configuration | V6, DOHC, 24‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 86.0 mm × 76.0 mm | |
Power output | 125 kW (170 PS) @ 5,500 rpm | |
Torque | 245 Nm @ 4,000 rpm | |
Fuel system | Sequential multi‑point fuel injection (SFI) | |
Emissions standard | Euro 3 | |
Compression ratio | 9.8:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt‑driven (DOHC, dual camshafts per bank) | |
Oil type | API SH/SJ, SAE 10W‑30 or 10W‑40 | |
Dry weight | 168 kg |
The Hyundai G6AT was used across Hyundai's NF, SM, and FO platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Sonata sedan and modified accessory brackets in the Santa Fe—and from 2005 the facelifted Trajet adopted updated ECU calibrations for improved cold-start emissions, creating minor ECU interchange limits. All adaptations are documented in OEM technical bulletins.
The G6AT's primary reliability risk is timing belt tensioner and idler pulley wear on early builds, with elevated incidence in high‑temperature or high‑load usage. Hyundai internal service data from 2004 noted pulley bearing failures in ~8% of pre‑2004 engines before 75,000 km, while UK DVSA MOT records show timing-related faults were rare but catastrophic when they occurred. Extended service intervals and use of non‑spec oil accelerate wear, making timely belt service critical.
Analysis derived from Hyundai technical bulletins (2003–2006) and UK DVSA failure statistics (2006–2016). 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 G6AT is generally reliable with proper maintenance. Early models (2002–2003) had timing pulley issues, but post‑2004 revisions improved durability. With timely belt changes every 60,000 km and correct oil, many engines exceed 250,000 km without major repairs.
Most common issues are timing belt tensioner/idler wear (pre‑2004), intake manifold gasket leaks, rear main seal oil leaks, and plastic thermostat housing cracks. These are documented in Hyundai TSBs TSB‑03‑07‑004 and TSB‑05‑01‑006.
The G6AT was used in the Hyundai Sonata (NF, 2002–2006), Santa Fe (SM, 2002–2006), and Trajet (FO, 2002–2005) across GL, GLS, and SE trims. All are Euro 3 compliant mid-size vehicles with transverse V6 mounting.
Modest gains are possible via intake/exhaust upgrades and ECU remapping, typically +8–12 kW. The DOHC V6 supports higher RPMs than inline‑4 variants, but forced induction is not recommended without internal reinforcement and upgraded cooling.
In a 2004 Santa Fe 2.7 GLS, real-world consumption is ~11.2 L/100km (city) and ~8.1 L/100km (highway), or about 26 mpg UK combined. With gentle driving, 28–30 mpg UK is achievable on mixed routes.
Yes. The G6AT is an interference engine. If the timing belt fails, pistons will contact open valves, causing severe internal damage. This makes strict adherence to the 60,000 km belt replacement interval essential.
Hyundai specifies API SH/SJ 10W‑30 or 10W‑40 mineral or semi-synthetic oil. Full synthetic is acceptable if it meets the same API standard. Change every 10,000 km or 6 months to protect the timing system and valve train.
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)
UK type-approval authority for automotive products.
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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