The dog ran as fast as a race car is an example of ...

This is an example of a simile.

Explanation:

A simile is when you compare two unlike things, in this case it's a dog and a car, using comparison words, "like," or "as." This is a simile because the sentence is comparing a dog to a car, and uses the comparison word, "as."

a simile.

Explanation:

involves the comparison of one thing with another thing of a different kind, used to make a description more clear