How to keep a car maintenance log that's actually useful

Most service records are a stamp in a booklet, a pile of receipts in the glovebox, or nothing at all. That's fine until you need to know when the timing belt was done, which brake pads you fitted last time, or what to tell a buyer. A good log answers those questions in ten seconds. Here's what to write down and why.

What to record for every job

• Date and mileage. Most service intervals are "whichever comes first": kilometres or months. Without both, you can't tell when the next one is due.
• What was done, in plain words: "front brake pads and discs", not just "brakes".
• Part numbers and brands. The single most useful thing to record. Next time you need the same part you search the number instead of guessing from the car's model and year, and you know whether the cheap brand lasted.
• Where you bought it and what you paid, including VAT and shipping. It shows what the car really costs you, and where to buy next time.
• Who did the work: you, a friend, or a garage (and their labour cost).
• The receipt. A photo is enough. Useful for warranty claims, and for proving the work to a buyer.

Typical service intervals

These are common ranges, not rules. Your car's manual (or the manufacturer's service schedule) is the only reliable source, and hard use, short trips, towing or an old engine all shorten them.

• Engine oil and filter: roughly every 10 000–30 000 km or once a year. Older cars and short trips: the lower end.
• Air filter: around every 20 000–40 000 km, sooner on dusty roads.
• Cabin (pollen) filter: about once a year.
• Brake fluid: usually every 2 years, whatever the mileage, because it absorbs water.
• Timing belt: anywhere from 60 000 to 180 000 km or 4–10 years depending on the engine. This one matters most: on many engines a snapped belt destroys the engine. If you don't know when it was last changed, assume it's due.
• Spark plugs (petrol): from 30 000 km for basic plugs to 100 000 km or more for long-life ones.
• Coolant: often every 4–5 years on modern long-life coolant.

Paper, spreadsheet or app?

A notebook stays in the car and needs no battery, but you can't search it and it gets lost with the car. A spreadsheet is searchable and free, but it's awkward on a phone in a cold garage, and receipts end up somewhere else. An app keeps entries, part numbers and receipt photos together and can remind you when something is due.

Whatever you choose, the habit matters more than the tool: write it down the same day, while you still have the receipt and know the mileage.

It pays off when you sell

A buyer who can see dated work with mileages and part numbers trusts the car more than one with a stamped booklet and "it's been looked after". A clear history is one of the few things that makes an older car easier to sell, and it costs nothing but the habit. Here is what such a history looks like when a seller shares it.