Every car owner has faced the oil change conundrum. The little sticker in the corner of your window gives you two ultimatums: a mileage and a date at which you need to change that oil. Maybe it’s only been two months, or maybe it’s been five months and the odometer is still miles from the target printed on the sticker. Which deadline is more important? How do you know when an oil change is overdue? Will the guys at the express garage glare at you disapprovingly when they see what you’ve done? Ask.cars gets to the bottom of the oil change dilemma.