Maybe you should try going to tirerack.com or tires.com and seeing what tires they suggest to replace the originals. Usually, they know the original size.
I'm surprised no one on here that knows has replied. Maybe someone could just walk outside and look, but I don't have the 16"s that came on my 2000 anymore, so I can't.
Good luck.
Yay... 200 [tech] posts in ~4 years!!!