The Vauxhall D 20 DTH is a 1,956 cc, inline‑four turbo‑diesel engine produced between 2015 and 2021. It features common‑rail direct injection, a single variable‑geometry turbocharger (VGT), and dual overhead camshafts (DOHC). In standard form it delivered 125 kW (170 PS) and 400 Nm of torque, with higher-output variants reaching 143 kW (195 PS) and 450 Nm.
Fitted to models such as the Insignia B and Astra K, the D 20 DTH was engineered for strong mid‑range pull and motorway refinement. Emissions compliance was achieved through exhaust gas recirculation (EGR), a diesel oxidation catalyst (DOC), and a diesel particulate filter (DPF), enabling Euro 6b compliance across all markets.
One documented concern is EGR cooler internal leakage, which can introduce coolant into the intake system and cause hydrolock. This issue, highlighted in Vauxhall Service Information Bulletin 05‑18‑12, is linked to thermal fatigue in early‑production EGR coolers. From mid‑2017, Vauxhall introduced a revised EGR cooler with improved metallurgy and flow path design.
All production years (2015–2021) meet Euro 6b emissions standards (VCA UK Type Approval #VCA/EMS/5680).
The Vauxhall D 20 DTH is a 1,956 cc inline‑four turbo‑diesel engineered for mid‑size and compact models (2015–2021). It combines Bosch common‑rail injection with a single variable‑geometry turbocharger to deliver strong low‑ and mid‑range torque and refined highway cruising. Designed to meet Euro 6b standards, it balances performance with emissions control and fuel economy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,956 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 83.0 mm × 90.4 mm | |
| Power output | 125–143 kW (170–195 PS) | |
| Torque | 400–450 Nm @ 1,750–2,500 rpm | |
| Fuel system | Bosch CP4.2 common‑rail (up to 2,000 bar) | |
| Emissions standard | Euro 6b | |
| Compression ratio | 16.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single variable‑geometry turbo (Garrett) | |
| Timing system | Chain (front‑mounted) | |
| Oil type | DEXOS2 (SAE 5W‑30) | |
| Dry weight | 158 kg |
The VGT turbo provides strong low-end torque ideal for mixed driving but requires strict adherence to 15,000 km or 12-month oil change intervals to protect the timing chain and turbo bearings. DEXOS2 (5W-30) oil is critical due to its low-SAPS formulation, which safeguards the DPF and aftertreatment system. Frequent short trips increase soot loading; occasional highway runs (≥60 km/h for 15+ minutes) are recommended to trigger passive DPF regeneration. The Bosch CP4.2 fuel pump demands ultra-low-sulfur diesel (EN 590) with adequate lubricity—avoid biodiesel blends above B7. Pre-2017 engines should be inspected for EGR cooler integrity per SIB 05 18 12.
Oil Specs: Requires DEXOS2 (5W-30) specification (Vauxhall Owner Manual 2015+). Meets ACEA C3 and API SN standards.
Emissions: Euro 6b certification applies to all 2015–2021 models (VCA Type Approval #VCA/EMS/5680). Confirmed via NEDC testing.
Power Ratings: Measured under UN ECE R85. Output verified on NEDC-compliant dyno per Vauxhall PT‑2022.
Vauxhall Technical Information System (TIS): Docs V5012, V5015, SIB 05 18 12
VCA Type Approval Database (VCA/EMS/5680)
EU Regulation (EC) No 715/2007 (Euro 6)
The Vauxhall D 20 DTH was used across Vauxhall's EMP2 and E2XX platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced mounts in the Insignia B and revised airbox routing in the Astra K—and from mid‑2017 the EGR cooler was updated to address thermal fatigue, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the oil filler neck (Vauxhall TIS V5018). The 7th VIN digit indicates engine family ('H' for D 20 DTH). All units feature black plastic cam covers with integrated coil packs and a visible DPF in the exhaust system. Critical differentiation from earlier 2.0L diesels: D 20 DTH uses a CP4.2 high-pressure pump and front-mounted chain. Service parts for EGR coolers differ pre- and post-06/2017 per SIB 05 18 12.
The D 20 DTH's primary reliability risk is EGR cooler internal leakage, with elevated incidence in pre‑mid‑2017 builds under high‑load or stop‑start conditions. Vauxhall internal data from 2019 indicated a notable uptick in EGR cooler replacements before 100,000 km, while UK DVSA records show minimal DPF‑related MOT failures due to robust regeneration logic. Thermal stress and marginal coolant chemistry make EGR cooler integrity critical.
Analysis derived from Vauxhall technical bulletins (2015–2021) and UK DVSA failure statistics (2016–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL D-20-DTH.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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