Oil additives - the heart of the matter.

This article covers every substance, without exception, that anyone might advise you to pour or add into your engine besides engine oil.

Some call their product an "additive," others a "supplement" — call it what you like, the substance of the matter doesn't change: you need to add absolutely NOTHING to the engine besides oil — and that's exactly what this article is about.

You can read about how the additives already built into every engine oil at the factory work in the article about how engine oil is made. Here, by "additives" we mean specifically what consumers add to engine oil themselves.

It's commonly believed that whether or not to use additives (supplements) in engine oil is a question akin to choosing a religion.

In reality, once you understand what additives are and how they work, the answer to this question can become obvious.

Everything you'll read in this section is nothing more than a case for the following plain truths:

1. Any additives added to engine oil cause irreparable harm to the engine and ultimately lead to the need for its replacement or overhaul.

2. Additives can produce an immediate effect (for instance, a small delay before an overhaul or engine replacement), but you need to understand that this effect is most likely not going to be especially significant, and it certainly won't be long-lasting to any meaningful degree. And repairing an engine after it's been run on additives is much harder, more expensive, and riskier in terms of the outcome.