Yeah, read my post! I may be one of the hundreds always reading the owner's manual first for any new cars we bought. And I do all the maintenance and repairs by myself too unless they are under warranty. Like I said, I followed the manual and set my 2016 CX-5 oil change interval to "Flexible"; but I couldn't find the selection of "Flexible" on my friend's. The only explanation to me is his has earlier version of software which doesn't support "Flexible" oil change interval.
Personally I'd like to find out the answer of the same question too.
By using flexible oil change interval, the manual says "Mazda genuine 0W-20 Oil and Castrol 0W-20 Oil are required to achieve optimum calculation performance."
I also found out from my dealer while I was asking about the "free oil change" offered by many dealers when you buy the car from them. The parts guy showed me the oil their service used for "standard" or "free" oil change. It was a brand I've never heard, and it costs less than a half of the genuine Mazda moly 0W-20 oil! I thought they will use at least the Castrol as specified in the owner's manual. The parts guy said, "No! unless you specify the Castrol or Mazda oil and pay additional accordingly, otherwise that unknown brand is the one you'll get!" I know even this unknown brand may still good enough to serve the SkyActiv high-compression engine, but I wouldn't risk it. With all the bad experience on dealer service I've had before, and I even heard the free oil change ending up the oil filter had never got changed, I'll get Mazda oil change package and change the oil by myself just for peace of mind. According to the posted video, the oil change on CX-5 is the easiest I've ever seen!
Just be aware of "free oil change" offered by your dealers! (headshake