The workshop consumables checklist: what to keep on the shelf
"Every 10,000 km" is the answer everyone repeats, and it is not a bad one, but it is not the whole story either. The right interval depends on your engine, your oil and, more than anything, how you actually drive. Here is the plain-English version.
What the manufacturers say
Most modern service schedules land somewhere between 10,000 km and 15,000 km, or every 12 months, whichever comes first. Some European makes with long-life oils stretch further; many older cars and most hard-working diesels sit nearer 5,000 to 10,000 km. The figure for your vehicle is in the owner's handbook, and it comes with a condition that is easy to miss: it assumes normal driving. The same handbook usually carries a second, shorter schedule for severe service, and a lot of Australian driving qualifies.
Time matters as much as kilometres
The 12 months part is not a formality. Oil degrades with time, heat cycles and moisture, not just distance. Every cold start lets a little condensation and unburnt fuel into the sump; on a car that does its kilometres in a few long runs a year, the oil can be past its best long before the odometer says so. A car that only does 5,000 km a year still needs its oil changed every year.
Short version: follow the handbook interval, but shorten it if you do lots of short trips, tow, or drive in dust. When in doubt, pop in and ask us.
Why short trips are harder than the highway
An engine that never fully warms up does not burn off the condensation and fuel that sneak past the rings into the oil. Over months that thins the oil, dilutes its additives and reduces its protection. If your daily run is a few kilometres to the shops or the school, treat the car as doing severe service even though the odometer barely moves.
- Lots of short trips: change more often
- Towing or heavy loads: change more often
- Dusty or coastal conditions: change more often
- Mostly highway: you can run the full interval
Towing and dust
Towing a van or a loaded trailer puts the engine under sustained load and heat, which is what breaks oil down. Dust is the other enemy: a loaded air filter lets fine grit past, and grit in the oil is an abrasive. If the vehicle tows regularly or lives on dirt roads, bring the oil and filter change forward to the severe-service interval, and change the air filter more often than the handbook says.
Pick the right oil while you are at it
A full synthetic holds up longer under heat and load than a mineral or semi-synthetic, which is why the long intervals in modern handbooks assume one. Match the viscosity grade and the specification to the handbook (the grade is the pair of numbers such as 5W-30; the specification is the API, ACEA or manufacturer approval on the back label), and you get cleaner cold starts and better protection between services. Change the filter with the oil every time; a new oil through an old filter is half a service.
