Its a time based system, it doesn't actually tell you anything about the oil.

 

It is time or distance based, whichever is happening first.

 

my ticker went to 0% right at 7500 miles, i might have reached the "time" requirement too cause i put A lot of miles on my turck, 10K already in 5 months!

 

Oil Life and Oil Life Start Value

The oil life is displayed in percentages and is preset to a maximum of approximately 12,070 (7,500 miles) or 180 days. The oil life start value is used to increase or decrease the starting point of the oil life. The value can be changed back to the maximum of approximately 12,070 (7,500 miles) if the value was previously changed or to lower the value by 10% increments down to 30%. Each 10% reduction lowers the oil life in both mileage and the days.

For example, if the oil life start value is lowered to 50%, the maximum mileage is 6,035 km (3,750 miles) or 90 days. The oil life remains at the selected setting (50% in this example) until the driver changes the oil life start value. When the oil life (not oil life start value) is reset back to 100% following an oil change, the oil life resets to 6,035 (3,750 miles).