You have a Fiat Punto. You DON'T have a Ferrari. "Emre drives AS IF he had a Ferrari." = he drives fast like someone who drives a Ferrari

Minh has a great explanation. There is also a slang version you may hear, and was popular in teen movies. In this case "As if" is a complete sentence expressing doubt. However, it is not a good form to copy.

it's used when you want to explain something by using ( likening ) as : he is running as if he is a horse ( he is not a horse ..... but he likes the horse in his run )

" As if " means As something would be if ... sometimes, it shows disbelief in a conversation.

Thanks a lot for your important inform :)