After my first 10,000 miles went by without getting an alert telling me to do so, I just decided to change my oil anyway- after all it can't hurt. I changed my oil again at 20,000 miles- still no alert. Now this alert system goes off of how you drive the car supposedly and 98% of my driving is highway- my oil change alert just went on for the first time at 27,500 miles- just 7000 miles after my last oil change. Obviously it's not going off of actual oil viscosity or oil quality. an interesting but useless feature in my opinion. If it had a built in wall if 10,000 (change when needed or 10,000 mi whichever comes first) it would make me feel better about actually trusting it.