OE series (including OEZ 0W-20, OEM 5W-20, OEF 5W-30, OET 10W-30) has a service life of 5,000 kilometers or 4 months.
The service life of XL series (including XLZ 0W-20, XLM 5W-20, XLF 5W-30, XLT 10W-30, XLO 10W-40) is 1 10,000 km /6 months.
Signature series (including ASM 0W-20, AZO 0W-30, ALM 5W-20 ASL 5W-30, ATM 10W-30) have a service life of 20,000 kilometers or one year.
High performance and long life series (including AMO 10W-40 and ARO 20W-50)
European car series (including AEL 5W-30 and AFL 5W-40), service life: follow the maintenance mileage and time specified by the original factory.
Z-Rod high-performance engine oil (including ZRT 10W-30 and ZRF 20W-50), life: 5000km.
Racing engine oil (including RD20, RD30, RD50, etc. ) Suitable for all kinds of racing engines.
Diesel engine oil series (including OED 15W-40, AME 15W-40, DEO 5W-40 and HDD 5W-30)
QT should be the unit of liquid volume in the United States.