This is the oil I run in my Mirage right now...
I tested this oil in my previous car (a 2009 Pontiac G5 XFE that averaged 37.5 mpg). It is supposed to be good for 15,000 miles. I sent an oil sample to Blackstone around 9,000 miles, and here's what they had to say...
Mobil 1 claims this is a 15,000-mile oil, and it probably could be in use that long, but as we mentioned in the previous report, it depends on several factors. Your engine was doing well after this 9,425 mile oil run, so with a TBN of 2.8, we wouldn't be surprised if you could run this oil out to at least 12,000 miles.
It's hard to say if it'd make it to 15K miles without excess wear, but it's possible. Try 12K miles next and check back. If all is well at that time, 15K miles should be fine.
So I would say this... Anyone using extended oil change intervals (10K+ miles) should probably be backing it up with an annual oil analysis to make sure you are not pushing the limits of the oil.
By the way...I just sent in a 5,000 mile oil sample to Blackstone Labs and I will be posting it as soon as it's done.
__________________________________________
View my fuel log 2015 Mirage ES 1.2 manual: 52.2 mpg (US) ... 22.2 km/L ... 4.5 L/100 km ... 62.6 mpg (Imp)