Under normal circumstances, most modern engine oil and gasoline brands work fine on their own to keep your engine running smoothly. But there may be cases where even the best of them could use a ...

Here are 2025's most popular questions and answers from The Journal's Car Doctor column, from rotating tires to oil changes.

Synthetic oil used to be something only performance cars needed, but not anymore. Now it’s the manufacturer-recommended engine lubricant in many mainstream vehicles, such as the Subaru Forester and ...

High mileage oil sits in the same aisle as conventional and synthetic, but it promises something different: extra protection ...

Car maintenance can be as difficult as it is messy. This is primarily because there are just so many fluids involved. Fluids of the darkest, stickiest, most potentially dangerous sort, in many cases.

It doesn't matter if you have a hybrid or conventional gas-powered car, a good motor oil can make the difference between a long-lasting engine and a sputtery ride. Here's what you should look for when ...

For years, drivers were told that they needed to change their car's oil every 3,000 miles. But as engines have grown more efficient and oil formulas have improved, that rule of thumb is no longer a ...

Most people understand that motor oil is a vital component for the internal combustion engines that power most of our cars. Not only does oil act as a lubricant, allowing internal moving parts to ...

When temperatures drop, the viscosity of the engine oil increases, meaning it becomes thicker. This change affects ...