Shell Helix Ultra ECT C3 5W-30 is a fully synthetic engine oil featuring Shell's most advanced emissions-compatible technology. Engineered using Shell PurePlus Technology — a unique process that produces synthetic base oil from natural gas — it delivers exceptional engine cleanliness, unsurpassed sludge protection, and enhanced fuel economy for modern petrol and diesel engines. Today's engines demand more from their oil than ever before. Tighter tolerances, higher pressures, and stringent emissions standards mean that only the most advanced fully synthetic oils can deliver the protection and performance modern vehicles need. Shell Helix Ultra ECT C3 5W-30 is specifically formulated to meet these demands — keeping diesel particulate filters (DPF) clean to maintain engine performance, protecting catalytic converters from ash build-up, and reducing engine friction to provide up to 1.7% greater fuel economy. Shell Helix Ultra ECT C3 5W-30 carries approval from BMW, Mercedes-Benz, and GM, making it suitable for a wide range of modern petrol and diesel engines requiring a C3-specification 5W-30 fully synthetic oil. Its low-ash SAPS formulation ensures compatibility with DPF-equipped vehicles, protecting your emissions system and your engine for the full drain interval. Always refer to your vehicle owner's handbook to confirm the correct oil specification for your vehicle. Fully synthetic 5W-30 C3 engine oil – approved by BMW (LL-04), Mercedes-Benz (229.51 / 229.31) & GM dexos2 Shell PurePlus Technology – base oil produced from natural gas for exceptional purity and engine cleanliness Advanced emissions-compatible formula keeps diesel particulate filters (DPF) clean and catalysts protected Reduces engine friction for up to 1.7% greater fuel economy Unsurpassed sludge protection – actively cleans the engine throughout the full drain interval 5 litre format – ideal for a full oil change on modern BMW, Mercedes-Benz, GM and other European engines Specifications & Approvals ACEA C3 API SN BMW Longlife-04 MB Approval 229.51 / 229.31 GM dexos2 Chrysler MS-11106 Frequently Asked Questions Is Shell Helix Ultra ECT C3 5W-30 fully synthetic? Yes. Shell Helix Ultra ECT C3 5W-30 is a fully synthetic engine oil. It is produced using Shell's patented PurePlus Technology, which synthesises base oil from natural gas rather than crude oil, resulting in an exceptionally pure base oil with fewer impurities than conventional synthetic oils. What cars is Shell Helix Ultra ECT C3 5W-30 approved for? Shell Helix Ultra ECT C3 5W-30 carries OEM approvals from BMW (Longlife-04), Mercedes-Benz (229.51 / 229.31), GM (dexos2), and Chrysler (MS-11106). It meets the ACEA C3 and API SN specifications, making it suitable for a wide range of modern European and American petrol and diesel engines. Always check your owner's handbook to confirm the correct specification for your vehicle. What is the difference between Shell Helix Ultra ECT C3 and Shell Helix Ultra 5W-30? Both are fully synthetic 5W-30 oils, but they serve different applications. Shell Helix Ultra ECT C3 is an emissions-compatible (ECT) formulation with a low-SAPS (Sulphated Ash, Phosphorus, Sulphur) formula, specifically designed for vehicles with diesel particulate filters (DPF) and catalytic converters — meeting the ACEA C3 standard and BMW LL-04 / MB 229.51 approvals. Shell Helix Ultra 5W-30 meets the older ACEA A3/B3 and A3/B4 standards and is suited to vehicles without strict low-SAPS requirements. Always verify against your handbook. Is Shell Helix Ultra ECT C3 5W-30 suitable for diesel engines with a DPF? Yes — this is one of its primary design purposes. Shell Helix Ultra ECT C3 5W-30 uses a low-ash SAPS formulation that prevents the ash build-up that can block diesel particulate filters. It actively helps keep the DPF clean to maintain engine performance and protect the emissions system over the full service interval. How often should I change Shell Helix Ultra ECT C3 5W-30? Shell Helix Ultra ECT C3 5W-30 is formulated to protect for the full manufacturer-recommended drain interval, including extended service intervals. For most modern BMW and Mercedes-Benz vehicles this is typically between 10,000 and 18,000 miles, or as indicated by your vehicle's condition-based service display. Always follow your manufacturer's service schedule.