Quick answer: a useful car maintenance log records the odometer reading, the service performed, and the date for every oil change, tire rotation, and major service — kept in one place you can check before the next one is due, not scattered across old receipts and vague memories of “sometime last year.”
Why “I think it was around 60,000 km” isn’t good enough
Most service intervals are defined by mileage, not calendar time — an oil change “every 8,000 km,” tires rotated “every other oil change.” Without a logged odometer reading at each service, you’re left guessing, which tends to go one of two ways: servicing too early and paying for work you didn’t need, or servicing too late and accelerating wear on the vehicle.
A log fixes this by turning “I think it’s about due” into “last done at 76,400 km, due again around 84,000.”
What to log at every service
- Odometer reading at the time of service — the single most useful number in the whole log.
- What was done — oil change, tire rotation, brake pads, etc. Be specific; “serviced” a year from now tells you nothing.
- Date, for the services that run on a calendar interval (registration, timing-belt age limits) rather than mileage alone.
- Cost, if you also want to track running expenses over time — optional, but useful for budgeting a used car’s true cost of ownership.
Common service intervals
Always defer to your specific vehicle’s manual — intervals vary by make, model, and driving conditions — but as a general reference point:
| Service | Typical interval |
|---|---|
| Oil change (conventional oil) | Every 5,000-8,000 km (3,000-5,000 mi) |
| Oil change (synthetic oil) | Every 10,000-16,000 km (6,000-10,000 mi) |
| Tire rotation | Every 8,000-12,000 km (5,000-7,500 mi), or every other oil change |
| Air filter | Every 15,000-30,000 km (10,000-20,000 mi) |
| Brake pads | Every 40,000-65,000 km (25,000-40,000 mi), highly usage-dependent |
| Timing belt (if equipped) | Every 100,000-160,000 km (60,000-100,000 mi), or a set number of years |
Keeping the log somewhere you’ll actually use
A log only works if updating it takes seconds, not minutes — and if it’s visible to whoever ends up driving the car to the next appointment, not just the person who originally set it up. Hommato treats the odometer log as its own timeline (log a reading whenever you like, see it plotted against service dates) sitting next to the same shared household record as the bills and warranties, so “what’s due and when it was last done” is a glance, not a search through old texts and receipts.
FAQ
Should I log mileage even between services, or only at service time? Logging only at service time is enough for most people — the reading at each service is what lets you calculate the next interval. Logging in between is only useful if you specifically want a mileage trend over time.
What if I don’t know when the last service was done? Start the log now with your current odometer reading and whatever you can find (a receipt, a sticker on the windshield, a dealer record). An imperfect starting point is still better than none — the log gets more useful with every entry from here.
Do electric vehicles need the same kind of log? Yes, though the specific items differ — tire rotation and brake service still apply, oil changes don’t, and battery-related checks are usually calendar- or mileage-based per the manufacturer’s schedule. The same log-the-mileage-and-date approach works either way.
Is a service due by mileage or by date, whichever comes first? Typically both — manufacturers usually specify an interval like “8,000 km or 12 months, whichever comes first,” which is exactly why tracking both the odometer reading and the date matters, not just one or the other.