More Oil Questions - What is really what?

[barryware]

Hello All...

Ok it has been confirmed I am an idiot as I am the guy that over filled the crankcase on my first oil change.

Now that we are past that.....

How can you tell if an oil that states it is synthetic is really synthetic?

After reading a few posts here, it was stated that Mobil 1 for instance is not really a synthetic.

I went to the mobile 1 website and in reading the information there, it pretty much states that mobile 1 is a true synthetic.

When I bought my oil, I purchased Mobile 1 super-syn which just like the regular mobile 1, states it is a fully synthetic oil on the bottle.

The super-syn also stated that it is good for 15,000 miles, guarantied and the other, less expensive mobile 1 gave no mention about the protection mileage.

So.. WTF? Is there a secret code on the bottle or some other kind of sign to know? Hence, my boggle