Here's why:
* "Good" is an adjective, but we need an adverb to modify the verb "runs."
* The correct adverb to use is "well."
Therefore, the correct sentence is: "The car runs well."
Here's why:
* "Good" is an adjective, but we need an adverb to modify the verb "runs."
* The correct adverb to use is "well."
Therefore, the correct sentence is: "The car runs well."