* No Chemical Change: When you combine oil and vinegar, they don't react chemically to form new substances. They remain as oil and vinegar.

* Easily Separated: The two components can be easily separated. If you let the mixture sit, the oil will rise to the top because it's less dense than vinegar. You can also separate them by using a separator funnel.

* Heterogeneous: Oil and vinegar don't mix evenly. They form distinct layers, making the mixture heterogeneous.

Therefore, oil and vinegar meet the criteria of a mechanical mixture: no chemical change, easy separation, and heterogeneity.