Use the Delco syn blend, but change it at 5000 miles maximum, even if the OLM is still indicating 50% life left. The turbo rips that oil to shreds by 5000 miles.
For maximum protection while staying in warranty, a full synthetic dexos1 5w30 would be ideal. I've run Quaker State Ultimate Durability 5w30 with okay results changed at 7000 miles and sorta-bad results changed at 9000 miles.
If you're sticking with a full synthetic, change it at 7500-8000 miles at the latest, even though the OLM says it can go longer. With the 1.4T, mileage is the biggest determining factor on when to change the oil, not the OLM. Don't go past 8000 miles on a full synthetic, and sleep well at night.
Check to see if you have the DI engine. GM has had some problems with their 3.6 DI engines (Timming Chain replacement)
due to fuel dilution. They had to reset the OLM on these engines. 8000 miles may be too long.