The thinner in oil is the easier it pumps through the engine, which leads to a fuel economy improvement. We can all understand that, but there's a lot more to oil viscosity than how thick it is. I ...

The physical and chemical differences between these crude types determine how easy they are to refine and their market value.

Every fleet owner should know the basics about the viscosity of the lubricants they are using and why the viscosity matters. Fleets—especially mixed ones—require a variety of lubricants. This ranges ...

A recent study used various gas oils and blends with residual heavy oils in order to evaluate the predictability of four different correlations. The gas oils differed substantially in their ...

Putting vegetable oil in a car engine is a terrible idea and should never be done, or at least that's what some experts say.

Home mechanics have been pouring vegetable oil into engines for years, sometimes in the fuel tank, sometimes straight into ...

Given the chore of changing it every few months, the typical motorist realizes that engine oil degrades over time. Some will also notice the mysterious codes for the different grades—10W-40, 5W-30, ...