Which car maintenance records should you keep?

What should each maintenance record include?

A maintenance record proves that a specific job was done on a specific vehicle. The strongest ones carry the same fields every time, whether they live in a folder, a spreadsheet or an app. For do-it-yourself work, the receipt for the oil and filter plus a dated entry with the mileage is the practical equivalent of a shop invoice.

• Date and odometer reading prove the job was done on time against the manufacturer's schedule, by calendar and by distance.
• Work performed, parts and fluids name the service and show what went in: oil grade, filter, brake pad brand, coolant type.
• Who did it the shop's name and address, or "owner" backed by the parts receipts.
• Cost turns a pile of paper into the real cost of owning the car.
• VIN ties the record to the car rather than to you, which is what a buyer checks.

Does doing your own maintenance void a car warranty?

No. The FTC's consumer alert on auto warranties and routine maintenance says an independent mechanic, a retail chain shop or the owner can do routine maintenance and repairs without voiding the warranty. The same alert tells owners to keep all service records and receipts, whoever performs the work, including oil changes, tire rotations, belt replacements, brake pads and inspections.

That advice is the practical point. If a warranty claim is questioned, the dated receipt for the oil and filter and a log entry with the mileage are what show the service was done on schedule.

How do you find a used car's service history by VIN?

Start with the seller's folder, which is usually the most complete source, then ask the dealers that serviced the car, since many keep records by VIN and some will share them. A commercial vehicle history report can list reported service visits; Kelley Blue Book notes that these reports include only reported events and will not show work done in a driveway. A government NMVTIS report covers title brands, the latest reported odometer reading and salvage history, and deliberately no maintenance.

• Owner's own records the most complete history, as good as the owner's habits.
• Dealer service records reliable for work done there, blind to other shops and home work.
• Commercial history report reported service visits only.
• NMVTIS report title, odometer and salvage data, no maintenance.

Is a spreadsheet, a folder or an app best for maintenance records?

The best method is the one you keep up with. A paper folder holds the original receipts but reminds you of nothing. A spreadsheet is free and searchable, but it depends on opening it after every service and typing the mileage yourself. An app can do the reminding and much of the recording.

WrenchTime, an iPhone app for cars and motorcycles, logs each completed service in its Care tab with the date, odometer reading, cost and notes, and can queue the next occurrence in the same step. It keeps an odometer audit trail showing every change and where it came from, stores the VIN on the vehicle, and exports a per-vehicle CSV or PDF with totals. The guide to iPhone maintenance apps covers what such a log should do. Keep the original receipts either way: the log organizes the history, the receipts prove it.

How do maintenance records help when you sell a car?

A complete, dated history answers the first thing a buyer asks, whether the car was looked after, before it becomes a price negotiation. Before listing, sort every invoice by date, make sure each one shows the mileage, and pull out the big-ticket jobs: timing belt, brakes, tires, battery and fluid services. A one-page summary of dates, mileage and work done, with the full folder offered to serious buyers, makes the car easier to trust. A fuel log kept in the same place also shows steady use over time.