Shell Helix Ultra ECT C3 uses advanced technology to ensure compatibility with exhaust emission control systems and protection of particulate filters, which translates into high engine efficiency. This oil reduces friction in internal engine components, contributing to fuel economy. Shell Helix Ultra ECT C3 is a fully synthetic engine oil, formulated with the latest technology to ensure compatibility with exhaust emission control systems. It protects both catalytic converters in petrol cars and particulate filters in diesel engines. It also acts as a barrier against the formation of ash, which can clog the exhaust system and reduce engine efficiency. This oil is suitable for use in modern petrol, diesel and particulate filter equipped engines and gas engines.