Severe service
I wouldn't go an entire year/7500 on ANY oil for 100% city driving. I would install an engine timer and change out the full synthetic oil every 200hrs. The other option is a 6 month 3750 interval, regardless oil marketing.
You need a UOA with TBN/TAN/oxidation and particle count to see if ANY oil/filter combo is capable of your chosen interval. Otherwise, you are driving blind with marketing.
Your replaced catalytics weren't caused by the oil. So, don't have trauma. Just don't buy another product from the company that manufactured your CTS, or use generic catalytic converters.
I liked the CX-5. Got a bit expensive with some options. Didn't think we'd get use to the center console radio controls stuff. But, the 6-speed 2.5 city commuter combo was perfect driver, IMO. We avoided turbos and CVTs, and it was a tough call among the 2.4/6peed Sportage and CX5. She took the Sportage since she didn't care for silly gimmick screens used by most now.
Keep it clean with top tier fuel, if available or equivalent high quality name brand fuel. LSPI in a non-turbo an issue? Regardless, 13:1 compression ratio on a non-turbo... would make me use premium always. A spraycan or bottle a year of IVD cleaner is something you should consider, along with a quality name brand or PEA based FI cleaner added to the tank.
I don't worry about sulfated ash in my oil. And, I'd rather replace a catalytic vs an engine!
