Why 20W oil and not 30?

[Rhinopolis]

Thanks, and yes, that reminds me that I must renew my Preferred Customer subscription/status.

Do they still make an EaO oil filter for this car (I know that they dropped MANY specific models from the line up recently)?

That's the same oil my brother uses in his '06 LS2 C6.

It's filter model "E a 15k 51" that is the recommended filter to use on the FiST.