Originally Posted By: frenchboy
First of all congratulations on your purchase
I owned an 3.2 CTS Sport Luxury & I loved that car.
I used different oils... Shell Helix Ultra 5W30, Castrol 0W30 and finally GM DEXOS 2 5W30 (bought on ebay).
No problems during the 7500/10000km OCI with Shell & GM...