The wrench is a remined for when the oil needs to be changed. Beside that is a number to tells you what other service is needed. Look in your owners manuel and it will tell you the number and the recommended service that the number stands for. The % is time left before a oil change is needed. I use that instead of the miles or time recomended. When you had the oil changed, they may not have reset the reminder. I recently went on a trip and on the way back the % went to 0 and then it starts counting backward. That is the miles overdue for the oil change.