Loading Maintenance Interval Tracker…
Several items, each with its own interval and its own last-done point, sorted by how close they are. An item can be watched on distance, on time, or on both, and one with both is reported against whichever arrives first.
Every interval on this page is one you type in from your own service schedule. Nothing here knows what an oil change, a brake fluid change or a cambelt is supposed to be done at, and the correct figures differ between two cars parked next to each other. Read them out of the manual for your car.
Five columns, in this order: name, odometer when last done, mileage interval, date last done, months interval. Put a dash in any column you do not track — an item watched on time alone needs only the last two. Dates are YYYY-MM-DD, and a line starting with # is ignored.
Optional. Dates the mileage limits.
Add an item or two, then give the odometer reading. Each item needs an interval and the point it was last done at.
Two items with the same name are ordinary here — a filter at each end, a pair of axles, the same job done twice — so the second one is numbered rather than folded into the first. Give them names you would recognise on an invoice; the list is only as useful as the labels you can still read in three years.
If you do not know when an item was last done, do not guess it forward. A car bought second-hand with no history is a car where every interval starts from the day you bought it or from the last date you can actually evidence, and the honest entry is the pessimistic one. A stamped book, a garage invoice or a dated photograph of the odometer all count; a previous owner’s assurance does not.
Brake fluid, coolant, spark plugs, air and pollen filters, a timing belt, gearbox oil, a fuel filter: a car is a collection of parts on unrelated schedules, some measured in distance, some in months, several in both. Nobody holds twelve running totals in their head, so in practice the whole list is remembered as one vague sense that a service is due soon, and the item that actually matters is whichever one nobody happened to think about.
This tracker keeps each item separately with its own last-done point and its own interval, then orders the list by how far through its interval each one has travelled. The top of that list is the answer to the only question the page is asked, which is what needs attention next.
Comparing eleven hundred miles against seven months is not possible directly, so each item is measured as a proportion of its own interval instead. Something ninety per cent of the way through sorts above something halfway through regardless of whether the clock counting it is an odometer or a calendar, and anything past its limit lands at the top where it belongs.
Where an item carries both kinds of limit, the tracker reports the one nearer to expiry and ignores the other, because that is what the schedule means when it joins the two numbers with the phrase whichever comes first. Supply your yearly mileage as well and the distance limits acquire approximate dates, which makes a list mixing both kinds much easier to read as a plan.
Intervals are easy to look up and last-done points are not, especially on a car bought second hand where the history is a partly stamped book and somebody’s recollection. The temptation is to assume the previous owner kept on top of it, and that assumption is worth nothing: an unrecorded job is an undone job as far as planning goes.
Where you have no evidence, the honest entry is the pessimistic one. Use the date you took the car on, or the last point you can actually document, and let the tracker tell you something is due rather than flattering the record. A dated invoice, a stamp, or a photograph of the odometer taken on the day all count as evidence; a verbal assurance from a seller does not.
No schedule is built into this page and none ever will be. The figures differ between two cars parked next to each other, sometimes between two engine variants of the same model in the same year, and an invented average would be confidently wrong for most readers. Every interval on the list is one you copied out of your own service schedule.
That constraint is also what makes the tracker useful for things a published schedule never mentions. Wiper blades, a battery you would rather replace before it strands you, a tyre rotation habit, the annual inspection: anything with a sensible last-done point and an interval you have chosen yourself sits in the list beside the manufacturer items.
Use the date the car was first registered, or the day you acquired it if that is all you can evidence, and the item will show as far through its interval or already past it. That is the accurate reading of an unknown history rather than a pessimistic one.
Because two items genuinely can share a name — a filter at each end of the car, the front and rear of the same job — and folding them into one row would lose one of them silently. The second occurrence is numbered so both stay visible and separately tracked.
Only if you want to see them coming. Items bundled into a routine visit take care of themselves, so the list earns its keep on the long-cycle jobs that fall between services and on anything you arrange yourself rather than leaving to a booking.
Yes, and several should be. Leave the mileage columns as dashes and give only a last-done date with a number of months, which suits fluids and anything that degrades on the driveway rather than on the road.