The American Petroleum Institute will introduce a special Service Symbol Donut to help consumers identify the newly-approved FA-4 (PC-11) diesel engine oil. API approved two new diesel oil standards, ...

The American Petroleum Institute is introducing a special Service Symbol Donut designed to help buyers differentiate between the new API FA-4 and CK-4 service categories for diesel-engine oils. The ...

If you've ever bought a quart of motor oil for your vehicle, you've likely encountered the letters API somewhere on the label. In fairness, there are a lot of abbreviations, symbols and odd number ...

It’s an advanced, next-generation engine oil standard focusing on ultra-low viscosity oils for modern engines. When purchasing oil, look for the API Service Symbol "Donut" on the label, which is an ...