Owner manual states either 12 months or when Service Due is on to change oil. I ran 3000 miles or 3 months so far and Oil Life is 70%. I used to change oil every 5k or 4 months. at this rate, it seems i wil be changing at 7000 miles or so at 7-8 months, which seems quite long to me. Should I change at 6 months or when SErvice Due instead?

 

I changed out the oil in my old 3G in the first 1200 miles, because someone told me that the original factory oil wasn't good, and who knew how long that old was sitting in there before I took hold of it. I asked the service dept. and they said when it prompts you, then change it. So I'm going with that this time around, especially because I'm leasing, I kinda don't mind following their advice, so we'll see...?

Are you planning to keep the ride?

 

how does it determine the life of the oil? Time or miles? Or is there a small chemist in the engine department that does daily testing?

 

I have owned a few TLs and the MID depends on your driving style, I don't know the specifics, but it looks at RPM, idle, temps and some stuff to determine oil life. My dirving I woudl do oil at 30% left and that was typically around 5K miles. I also get facotry oil out at 2K and go synthetic.