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 ...

Using the best engine oil additive can help improve the performance and longevity of your engine in a variety of ways. Most change the viscosity of the engine oil. Some also provide a coating of sorts ...

Walk into any parts store and you'll see the rows of glossy bottles promising to stop engine wear, boost fuel economy, and make your old clunker run like it just rolled out of the factory. The auto ...

Snake oil. Mouse milk. Whiffle dust. Take your pick — few products have earned such unflattering sobriquets as aftermarket motor-oil additives. And for the very good reason that these promised ...

Aftermarket additives are a popular off-the-shelf item at truck stops and parts counters, but many of the necessary additives already are formulated in the diesel engine oils directly from the ...