Oil is oil, synthetic is synthetic.
Valvoline to Mobil 1 to Castrol, the motor will not know any different and they all must meet the same exact standards to be ran in a newer cars that call for dexos or whatever else. Cold weather testing is not something I will get into as certain oils do flow better at those temps but thats not what is important.
Your Cruze 1.4T can run the semi synthetic oil because it likely has or meets the dexos requirement that GM wants. Because it's turbo'd and the fact that they get so damn hot, I would change to a full syn just for that reason. A longer lasting oil is what I would want to run.
