IDEMITSU Zepro Diesel SAE 5W-40 is fully synthetic all-season engine oil. Properties. IDEMITSU Zepro Diesel SAE 5W-40 is designed to meet the requirements of European vehicles, including high-powered and turbocharged vehicles, using 100% synthetic base oil. It ensures excellent resistance to evaporation and trouble-free starting at extremely low temperatures. It has excellent lubricating properties at high and low temperatures. At very low temperatures, it has excellent thermal and oxidation stability, etc. Applications. IDEMITSU Zepro Diesel SAE 5W-40 is designed for modern diesel engines of passenger cars, SUVs and light trucks, turbocharged and not.