The Audi CSWB is a 1,984 cc, inline — four turbocharged petrol engine produced between 2015 and 2021. It forms part of the EA888 Gen 3B engine family, featuring direct fuel injection (FSI), variable valve timing, and integrated exhaust manifold for thermal efficiency. In standard tune it delivers 140 kW (190 PS), with peak torque of 320 Nm available from 1,500 rpm, enabling responsive urban and highway performance.
Fitted to models such as the 8V/8VFL A3, 8S/8Y TT, B9/B9L A4…
Production years 2015–2021 meet Euro 6b standards .
The Audi CSWB is a 1,984 cc inline-four turbocharged petrol engine engineered for compact and mid-size platforms (2015–2021). It combines TFSI direct injection with dual variable valve timing to deliver responsive low-end torque and smooth power delivery. Designed to meet Euro 6b standards, it balances performance with emissions compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,984 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 82.5 mm × 92.8 mm | |
Power output | 140 kW (190 PS) @ 4,200–6,000 rpm | |
Torque | 320 Nm @ 1,500–4,100 rpm | |
Fuel system | Bosch HDEV5 direct injection (up to 200 bar) | |
Emissions standard | Euro 6b | |
Compression ratio | 9.6:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single-scroll turbo with electronic wastegate (Honeywell) | |
Timing system | Timing chain (front-mounted, maintenance-free design) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 135 kg |
The Audi CSWB was used across Audi's MQB and MLB platforms with transverse (MQB) and longitudinal (MLB) mounting. This engine received platform-specific adaptations-shorter intake runners in the A3 and revised cooling routing in the A6-and from 2018 the facelifted B9L A4 adopted the Gen 3B+ update with enhanced GPF regeneration logic, creating software compatibility limits. All adaptations are documented in OEM technical bulletins.
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The CSWB's primary reliability risk is high-pressure fuel pump wear under low-fuel conditions, with elevated incidence in urban driving with frequent short trips. Internal Audi quality reports from 2018 noted a significant share of pre-2018 units requiring HPFP replacement before 100,000 km, while VCA MOT data links GPF clogging to stop-start driving in city environments. Extended idling and low-tank operation increase pump and filter stress, making fuel management and service interval adherence critical.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
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The CSWB is generally robust when maintained properly, but pre-2018 models have a known HPFP wear issue under low-fuel conditions. Later revisions (post-2018) improved pump durability and GPF management. Regular servicing, use of RON 98 fuel, and maintaining fuel levels above 10% significantly enhance longevity. Well-maintained units can exceed 150,000 km without major repairs.
Key issues include high-pressure fuel pump wear (especially below 10% fuel), gasoline particulate filter clogging in city driving, cold-start timing chain rattle, and moderate oil consumption. These are documented in Audi service bulletins and addressed through component updates and software revisions from 2018 onward.
The CSWB is found in the A3 (8V/8VFL), TT (8S/8Y), A4 (B9/B9L), A5 (B9/B9L), and A6 (C8) models from 2015 to 2021. It was used in both transverse (MQB) and longitudinal (MLB) applications. Variants include 35 TFSI and 40 TFSI, all meeting Euro 6b standards with GPF integration.
Aftermarket ECU tuning is common on the CSWB platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
In combined driving, expect 6.5–7.2 L/100km (41–39 mpg UK). Highway efficiency improves to ~5.8 L/100km (49 mpg), while city driving may reach 8.5 L/100km (33 mpg). Real-world figures depend on driving style, but GPF regeneration cycles can temporarily increase consumption. Models with S-tronic transmission achieve slightly better economy.
Yes. The CSWB is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. While the chain is maintenance-free, tensioner wear can cause slack. Cold-start rattles should be investigated promptly to avoid costly repairs.
Audi specifies 5W-40 synthetic oil meeting Audi Longlife 05 (or newer) standards. This oil ensures proper turbo, VVT, and HPFP lubrication. Change intervals are up to 15,000 km or 1 year, but shorter intervals are advised for stop-start driving. Using incorrect oil can accelerate HPFP and chain wear.
Comprehensive technical documentation and regulatory references
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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.
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