[tradewind]

I'd be careful with the 0W-30. Too low a viscosity could mean insufficient lubrication.

 

[tradewind]

I have never used synthetic oil. I know it is supposed to last longer. Other than than, do you feel other difference, fuel economy, for instance?

Do you still change oil every 3k miles with synthetic?

 

[tradewind]

Thank you very J33. I have an XE, no DIC. So I will just have to follow the book then on mileages...

I am wondering how the oil life is calculated. Does the car actually do a on-board test/analysis of the oil property? If so, what does it measure? Viscosity? Free carbon concentration? Alternatively, it can simply run an algorithm of mileage and elapsed time without actually assessing the oil condition. The algorithm resets itself at each service. You could have put cooking oil there and it'll still give you a % of life left.

 

[tradewind]

I just found out that they do tell remained oil life on my XE DIC. With that it's easy to find out how they calculate the oil life. The next time I change oil, if the oil life automatically shows 100%, then there is a sensor actually analyzing the oil. If I need to manually reset the oil life, then they are running a mile/time algorithm.

 

[tradewind]

You do have to reset after an oil change. I believe the oil life monitor bases it's percentages on time, mileage and driving habits.
Tim C.

I figured as much since my XE also has it. Once the display is there, the oil life feature is entirely software based, no added hardware cost. If GM has to add sensors to actually analyze oil property, XE wouldn't have had it.

Thanks TSC1969.