The Audi CTHG is a 1,968 cc, inline — four turbo — diesel engine produced between 2015 and 2018. It belongs to the Volkswagen Group’s EA288 engine family, designed specifically for Euro 6 compliance. Featuring common rail direct injection, variable geometry turbocharging (VGT), and dual overhead camshafts, it delivers 110 kW (150 PS) and 340 Nm of torque, providing strong low — end pull and refined performance across compact and mid — size Audi models.
Fitted to the 8V A3, 8W…
All CTHG engines meet Euro 6a standards (VCA UK Type Approval #VCA/EMS/7421). No Euro 6d-TEMP variants exist for this engine code.
The Audi CTHG is a 1,968 cc inline-four turbo-diesel engineered for compact and mid-size models (2015–2018). It combines common rail injection with variable geometry turbocharging and SCR-based aftertreatment to deliver strong low-RPM torque. Designed to meet Euro 6a standards, it balances real-world drivability with strict emissions compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,968 cc | |
Fuel type | Diesel | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged with variable geometry turbo (VGT) | |
Bore × stroke | 81.0 mm × 95.5 mm | |
Power output | 110 kW (150 PS) @ 3,250–4,200 rpm | |
Torque | 340 Nm @ 1,750–3,000 rpm | |
Fuel system | Bosch CRS 2-20 common rail (up to 2,000 bar) | |
Emissions standard | Euro 6a | |
Compression ratio | 16.5:1 | |
Cooling system | Water-cooled with electric coolant pump | |
Turbocharger | Single variable-geometry turbo (BorgWarner) | |
Timing system | Chain-driven (rear-mounted; low wear risk) | |
Oil type | Audi Longlife Diesel 504.00 / 507.00 (SAE 5W-30) | |
Dry weight | 148 kg |
The Audi CTHG was used across Audi's MQB platform with transverse mounting and shared within the Volkswagen Group for longitudinal applications in select models. This engine received platform-specific adaptations-shorter intake tracts in the A3 and revised cooling routing in the Q3-and from 2017 the facelifted A4 B9 adopted the updated EA288evo variant with enhanced EGR cooling, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The CTHG's primary reliability risk is EGR cooler failure on early builds, with elevated incidence in mixed driving cycles. Internal Audi quality reports from 2017 indicated a significant share of pre-2017 engines requiring EGR cooler replacement before 120,000 km, while UK DVSA records show increased DPF-related failures linked to coolant contamination in poorly maintained units. Short-trip cycles and extended idling increase thermal stress on the EGR system, making coolant quality and interval adherence critical.
Analysis derived from Audi technical bulletins (2015-2018) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
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The CTHG offers strong efficiency and refinement, but early models (2015–2016) had EGR cooler concerns under mixed driving conditions. Later revisions (post-2017) improved cooler durability, enhancing overall reliability. Regular servicing with Audi-approved oil (5W-30 Longlife Diesel 504.00) and timely EGR system maintenance greatly improve long-term dependability.
Key issues include EGR cooler leakage, turbocharger actuator sticking, intake carbon buildup, and AdBlue system faults. These are documented in Audi service bulletins and field reports. Proper maintenance, especially coolant and oil changes, significantly reduces the likelihood of major failures.
The CTHG was used in the A3 (8V), A4 (8W), and Q3 (8U) between 2015 and 2018. It also appears in select Volkswagen models like the Passat B8 as part of the EA288 family. All applications are diesel variants meeting Euro 6a standards.
Yes. The CTHG responds well to ECU remapping, with stage 1 tunes typically adding +25–40 kW. Stock internals support moderate tuning, but supporting mods (intercooler, exhaust) are recommended. Tuning should be performed by specialists familiar with EA288 emissions constraints.
In real-world driving, expect 5.0–6.0 L/100km (47–56 mpg UK) in mixed conditions. Highway efficiency improves to ~4.5 L/100km (~62 mpg UK). Fuel consumption varies with driving style and vehicle weight, but the engine's thermal efficiency helps maintain strong economy for a turbo diesel.
Yes. The CTHG is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. Immediate attention to any timing-related issues is essential to avoid costly repairs.
Audi specifies 5W-30 Longlife Diesel 504.00 / 507.00 synthetic oil. Oil changes should occur every 15,000 km or annually. Using correct oil is critical for EGR, turbo, and DPF system longevity.
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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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