The Renault 843 721 is a 1,461 cc, inline‑three turbo‑diesel engine produced between 2006 and 2010. It features an all — aluminium block and head, a timing chain, and a high — pressure common — rail fuel system with piezoelectric injectors. This compact powerplant was engineered for efficiency and low emissions, delivering 66 kW (90 PS) and 200 Nm of torque, making it ideal for urban and subcompact vehicles.
Fitted primarily to the Clio III and Twingo II, the 843 721 prioritis…
Production years 2006–2010 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/6789).
The Renault 843 721 is a 1,461 cc inline‑three turbo‑diesel engineered for subcompact hatchbacks (2006-2010). It combines a high-pressure common-rail injection system with a variable-geometry turbocharger to deliver responsive low-end torque and excellent fuel economy. Designed to meet Euro 4 standards, it represents Renault's push for diesel efficiency in its smallest platforms.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,461 cc | |
Fuel type | Diesel | |
Configuration | Inline‑3, DOHC, 12‑valve | |
Aspiration | Turbocharged | |
Bore × stroke | 76.0 mm × 85.5 mm | |
Power output | 66 kW (90 PS) | |
Torque | 200 Nm @ 1,750 rpm | |
Fuel system | Siemens VDO common-rail (up to 1,600 bar) | |
Emissions standard | Euro 4 | |
Compression ratio | 16.8:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Variable-geometry turbo (Honeywell) | |
Timing system | Chain-driven | |
Oil type | Renault RN0700 (SAE 5W‑30) | |
Dry weight | Not Available |
The Renault 843 721 was used across Renault's Clio III and Twingo II platforms with transverse mounting. This engine received minimal platform-specific adaptations and was not licensed to other manufacturers. All applications are documented in OEM technical bulletins.
The 843 721's primary reliability risk is EGR cooler failure, with elevated incidence in high-mileage or stop-start urban use. Renault internal service data indicated a high correlation between cooler failure and vehicles exceeding 100,000 km, while UK DVSA records show DPF-related issues as a common cause of emissions test failures. Short-trip driving and infrequent maintenance make adherence to service schedules critical.
Analysis derived from Renault technical bulletins (2006-2010) and UK DVSA failure statistics (2012-2023). 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 843 721 is generally reliable if its known weak points are addressed. The EGR cooler is the most critical failure item, often failing around 100,000 km. With the cooler replaced and regular maintenance (especially oil changes and DPF regeneration), these engines can easily reach 150,000-200,000 km without major issues.
The most frequent issues are EGR cooler failure leading to coolant loss, DPF clogging from short trips, turbocharger actuator faults causing loss of boost, and glow plug failures affecting cold starts. These are well-documented in Renault service bulletins and owner reports.
This 1.5 dCi engine was used in the first phase of the Clio III (2006-2010) and the Twingo II (2007-2010). It was consistently badged as the 1.5 dCi 90 across both models, indicating its 90 PS power output.
Yes, it has modest tuning potential. A simple ECU remap can safely increase power to around 105-110 PS and torque to 220-230 Nm. The engine is quite robust for its size, but supporting modifications are minimal. It's a popular choice for economical tuning due to its strong low-end torque.
Excellent. In a Clio III, expect real-world figures of 4.5-5.5 L/100km (51-62 mpg UK) on a mixed run. Highway cruising can yield under 4.0 L/100km (70+ mpg UK). Its small displacement and diesel efficiency make it one of the most economical engines of its era.
Yes, it is an interference engine. If the timing chain were to fail (which is rare but possible), the pistons would collide with the valves, causing significant internal damage. Fortunately, the chain is very durable and typically lasts the life of the engine with proper oil maintenance.
Renault specifies an oil meeting the RN0700 standard, typically a 5W-30 synthetic. Using the correct specification is vital for protecting the high-pressure components of the common-rail injection system and ensuring the timing chain tensioner operates correctly.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with RENAULT or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
RENAULT Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialRENAULT documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.
All external links open in new tabs. Please verify current availability of resources.