Adding engine oil, what weight?

[PeterJoyce]

I have a 2004 Boxster. I have read that there can be as much burnoff as 1 quart for every 1,000 miles. My Boxster has 1,600. So I want to add oil, the dipstick is just below half mark. What weight comes out of the factory as standard. I also cannot read the coolent level in the trunk. Is there an easy way to check it? Thanks!