After purchasing my 2014 Mirage ES CVT, I changed the engine oil to conventional for break-in, and drove it fast and hard for the first 3,000 miles. Oil was also changed a couple of times during that 3,000 miles - I didn't want all those glittery metal fragments circulating in the engine!
In the past year, I've settled on running conventional PYB 5W-30 along with a Wix or Wix rebranded oil filter.
Engine's purring, no oil burning issues at all, and I'm easily averaging 52+ mpg combined, with ~90% city and ~10% highway driving.