Referring to objects as "she" [duplicate]

Sometimes people are referring to mechanical objects as "she":

I love my car. She always gets the best service.

Are there any rules when it is appropriate to use "she" instead of it, and is "he" ever used in such context?

From http://en.wikipedia.org/wiki/Grammatical_gender#Animate_and_inanimate :

The pronoun "she" is sometimes used to refer to things which can contain people such as countries, ships, or vehicles, or when referring to certain other machines. This, however, is considered a stylistically marked, optional figure of speech. This usage is furthermore in decline and advised against by most journalistic style guides such as the Chicago Manual of Style.[9] If used, the terms she, her, and hers are always used, regardless of the entity's name - for example, "The U.S.S. John F. Kennedy (CVA-67) was laid down October 22, 1964. She was launched on April 1, 1967..."

"He" in reference to an inanimate object has not, as far as I'm aware, ever been common usage in English.

Gender is also used in English to refer to certain abstract ideas or institutions. For example, 'The Church always protects her own', or 'Justice unleashed her judgement'.