What's the thickest grade motor oil and which engines can use it?

Back in the early 20th century, there were only five motor oil grades. Today, there are more than a dozen for various types ...
AOL

5 Underrated Motor Oil Brands That Can Compete With Castrol

Castrol is known among car enthusiasts and everyday drivers alike as one of the industry's best motor oil brands. The company's lineup includes EDGE, GTX, and GTX Full Synthetic — oils for a wide ...
Forbes

Motor Oil Update: API Introduces New ‘SQ’ Service Category

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 ...