Loading Oil Change Interval Planner…
The interval is a number you read off your own service schedule, not one this page supplies. Give it here with the point the last change was done at, and the two limits — distance and time — are worked out against whichever arrives first.
This page holds no service schedule and will never suggest one. Intervals for a modern engine run from a few thousand miles to twenty thousand depending on the engine, the oil specification it takes, whether the schedule is fixed or variable and how the car is driven, and a figure guessed for the average car can wreck yours. Open the owner’s manual, find the interval it gives for your engine, and type that.
Leave blank if yours is given only in months.
Leave blank if yours is given only in miles.
Optional. Puts a date on the mileage limit.
Enter at least one interval from the manual, with the odometer reading or the date it was last done against it.
Many schedules carry a second, shorter interval for what the manual calls severe service: short trips that never warm the engine through, long idling, towing, dust, or a lot of cold starts. Plenty of ordinary commuting qualifies. If your manual lists two intervals, decide honestly which describes your driving before you type a number in, because the tool cannot see how the car is used.
The oil specification matters as much as the interval. A long-life schedule assumes an oil that meets a particular manufacturer approval, and filling with something cheaper that merely shares a viscosity grade does not carry the same interval. If the car has a variable service indicator, that light is doing this calculation from real driving data and beats any arithmetic done here.
Nothing here suggests how often oil should be changed, and no figure of that kind is built in. The correct number depends on the engine, on the oil specification the manufacturer approved for it, on whether the schedule is fixed or variable, and on how the car is driven — and across ordinary road cars it spans roughly five thousand miles at one end to twenty thousand at the other. A figure picked for the average car would be wrong for yours in a direction you could not predict, and being wrong in the generous direction damages an engine.
So the planner takes the interval as an input. Open the handbook, find the schedule for your engine, and type in what it says. This page then does the part that is genuinely fiddly: tracking two limits at once and working out which of them you will meet first.
Distance is only half of the schedule. Engine oil takes on moisture from condensation, picks up unburnt fuel and combustion acids that were never fully boiled off, and steadily consumes the additive package that handles detergency and wear protection. All of that continues on a driveway, which is why manufacturers publish a months limit beside the mileage one and join them with the words whichever comes first.
For a low-mileage car this is not a footnote, it is the whole schedule. Someone covering four thousand miles a year will meet a time limit repeatedly and might never reach the distance limit at all, and a driver who tracks only the odometer will believe the car is barely halfway through when it is already overdue. Reversing that is the reason this planner reports both limits and names the nearer one.
Many schedules print a second, shorter interval for conditions the manufacturer calls severe, and it is worth reading the definition rather than assuming it means something dramatic. Short journeys that never bring the engine fully up to temperature, long periods idling, towing, dusty roads, sustained high loads and a lot of cold starts all qualify on most lists. A short urban commute in winter can tick several boxes at once.
Whether that describes your driving is a judgement only you can make, and it changes which of the two printed numbers you should type in. The planner cannot see how the car is used, so it takes the interval you give it at face value and does the arithmetic against that.
A mileage limit has no calendar attached to it until you say how far you drive. Give the planner your own yearly mileage and it converts the remaining distance into an approximate number of days, which lets both limits be compared as dates and makes the nearer one obvious at a glance.
Treat that projection as a rough guide rather than a booking. Yearly mileage is uneven — a long summer trip or a month without the car moves it substantially — so the estimate is best used to decide roughly when to look at the odometer again, not to plan a garage visit down to the week.
Because there is no such number in general, only a number for your specific engine and oil. Publishing a plausible average would be inventing a reference figure, and anybody who followed it on a car with a shorter schedule would be running old oil for thousands of miles.
It can change it completely. Long-life schedules assume an oil meeting a particular manufacturer approval, and a cheaper product sharing only the viscosity grade does not necessarily carry the same interval. If you cannot confirm the approval, the shorter schedule is the safer assumption.
Generally yes, where one is fitted. A variable service indicator watches real operating data such as temperatures, trip lengths and engine load, so it is doing this calculation with information no arithmetic on a web page can reach. Use the planner alongside it rather than against it.
A small overrun on a fresh engine with the correct oil is unlikely to be dramatic, but the margin is not yours to spend repeatedly. Consistently running past the limit accelerates wear and sludge formation, and the damage accumulates quietly rather than announcing itself.