[meyerweb]

I believe it says Dexos 2 aproved oil for the Z06 C7 - ??? and a 5W30 or for track 15W50?? is this the correct??

Dexos 2 is the certification for Diesel engines. You want Dexos 1 for your C7. This site lists the current Dexos 1 approved oils.

dexos1? Gen 2 Brands | GM dexos® Licensing Program

Yes, 5W-30 for street use, 15W-50 for the track.

 

[meyerweb]

Not everyone is in the "Mobil 1" Club. Personally I use the Amsoil products in all of my vehicles.

I've had Mobil 1 in my car since new, because I got 4 free M1 oil changes courtesy of Chevrolet. Next change will probably be Penzoil Platinum Plus. Same price as Mobil 1 at my local auto parts store in 5 quart jugs. (Yeah, I can probably get M1 cheaper at WalMart, but I think that the Penzoil is probably better oil.) But the truth is that if you change the oil according to the OLM, and use a high quality synthetic, you'll wear out the rest of the car before the engine fails due to oil related issues.