I searched the forum, and couldn't come up with an answer: Does the filter life percentage display rely on some sort of sensor measuring how full the filter is, or is it just going by age/mileage? I have only 5800 miles on the car, and it says the filter life is 27%. I started driving the car December 2022. Based on the time and mileage, it seems like I am going to hit 0% well before 7500 miles and the free service. Please forgive me if this has been answered somewhere.

 

It's not based on filter loading. It's based on a number of factors that the algorithm uses to predict life. The oil life monitor is more aligned with time vs other factors but there are other factors that are taken into consideration in calculating fluid life.

 

From the description the filter life monitor is strictly based on mileage. If you divide 5800 by (1-0.27) you get 7945. The first filter change interval is 7500 +/-500 miles so you are on track.

 

I did the math and came up with the same result. Thought to read all of the posts before I provided redundant information.

 

Thank you all. I'm a product of public school math education, and calculated wrong.

 

Your number does seem a little off, but not in the direction you thought. I agree with the math others posted above. The Owner's Manual says that the life monitor is "based on the number of miles driven as outlined in the Service and Maintenance section." Reading that, I would have expected it to be based on going to 0% at 7500 miles, which is the number in the maintenance section. And so at 5800 miles I would have expected it to read 23% rather then 27%. However, suppose it had the 500 mile grace period built in (which is what @RKCRLR is getting at above) , so it was designed to go to 0 at 8000. Based on that, you would read...wait for it....27.5, or probably display 27, exactly what you have. And if it is based on going to 0 at 8000 miles, then at the other end of the grace period (7000 miles) it would read 12.5%, probably displaying 12%. If it was linear and had a built in grace period of +/- 500 miles. Of course it could be designed differently.

I think as the %life approaches 0, you may see a "change DCT filter soon" message, and then eventually a "change DCT filter now" message. My guess is that it will start to send that message when the %life is 10% but I don't know that. Someone should post the mileage when that message to "change DCT filter soon" or "change DCT filter now" first appears. Then we will know.

 

Will be interesting to see what happens between 7500 and 22500. And 22500 thereafter. I changed my fluid and filter at 2450. Will the life decline slope be increased as there is only 5000 miles between now and 7500. Or will the "change filter soon" now be offset by the early change. In all practicality, I'll be doing the three year fluid replacement and DCT filter at the same time so I'll never really know.