Every part of your car has its own lifespan, and each one needs attention at a different point. The problem is that most drivers rely on a single number from the service booklet, a number that assumes perfect conditions rarely found in practice. Here we have gathered every replacement interval in one place, with ranges and the conditions that shift them. For the actual contents of a minor or major service, see our dedicated guides. This page is focused solely on the question of "when."
Engine Oil and Oil Filter
The baseline rule is 10,000 to 15,000 km or once a year, whichever comes first. The oil filter is always replaced together with the oil, no exceptions.
That range is not fixed, though. If you mostly drive short city trips under 10 km, the engine never warms up enough to evaporate moisture from the oil. In that regime, oil ages much faster and we change it closer to the bottom of the range, at 8,000 to 10,000 km. Open-road driving and longer distances allow 12,000 to 15,000 km without concern.
Long-life intervals of 20,000 to 30,000 km prescribed by some manufacturers (VW and BMW in particular) deserve healthy skepticism in our conditions. Those intervals assume high-quality fuel with low sulfur content, a mild climate and mostly highway driving. Local fuel quality, city congestion and temperatures swinging from -15 to +40 degrees do not fit that profile. In our workshop, we regularly see engines with sludge deposits in cars whose owners faithfully followed the long-life schedule. If you want to know which oil suits your engine, check our guide to choosing engine oil.
Air, Cabin and Fuel Filters
The engine air filter is replaced at 20,000 to 40,000 km, depending on conditions. If you drive on dusty roads or in industrial areas, the filter will clog sooner and should be inspected as early as 15,000 km. Symptoms of a clogged air filter include higher fuel consumption, sluggish acceleration and a feeling that the engine "can't breathe." We covered diagnostics in detail in our air filter guide.
The cabin filter (pollen filter) is replaced every 15,000 to 20,000 km or once a year. It does not affect engine performance, but it directly affects the air you breathe inside the car. A clogged cabin filter means weak airflow through the A/C and heater, windows that are harder to defog and an unpleasant smell when the ventilation kicks in. Drivers who suffer from allergies will feel the difference immediately after a replacement.
The fuel filter on petrol engines typically lasts 60,000 to 100,000 km because it is integrated into the in-tank pump and is rarely serviced separately. Diesel engines are a different story: the fuel filter with its water separator is replaced every 30,000 to 50,000 km. Water in diesel fuel is a common issue, especially at lower-traffic filling stations, and a clogged filter can directly damage injectors and the high-pressure fuel pump.
Brake Fluid and Coolant
Brake fluid is replaced every 2 years, regardless of mileage. Brake fluid is hygroscopic, meaning it absorbs moisture from the air through micro-pores in hoses and fittings. With every percentage point of moisture, the boiling point drops. Fresh DOT4 fluid boils at around 230 degrees, but after two years with 3% moisture content that temperature can fall below 150 degrees. On a long mountain descent or during repeated hard braking, that becomes a real problem. Measuring moisture content takes about twenty seconds and we do it at every service visit.
Coolant (antifreeze) replacement depends on the type. Conventional silicate-based coolant (usually green) lasts 2 to 3 years. OAT coolant (organic acid base, usually orange or pink) lasts 4 to 5 years or 150,000 to 250,000 km. Hybrid types (HOAT) fall somewhere in between. The key is to follow the recommendation for your engine, because the wrong coolant type can cause corrosion at bimetallic joints in the cooling system. Between changes, check the level in the expansion reservoir; it should sit between the min and max marks on a cold engine.
Transmission Oil
Manual gearbox oil is officially labelled "lifetime fill," but in practice that means the lifetime of the gearbox under ideal conditions. Changing the oil every 80,000 to 120,000 km extends the life of synchronizers and bearings. Symptoms of old gearbox oil include difficulty engaging gears when cold and noise when shifting into a particular ratio.
Automatic, DSG and CVT transmissions require regular oil changes, a topic we covered in depth in our dedicated automatic transmission service guide. In brief, conventional automatics (ZF, Aisin) need a change every 60,000 to 80,000 km, DSG transmissions every 60,000 to 90,000 km depending on variant (wet or dry clutch), and CVTs have the shortest interval at 40,000 to 60,000 km. Dirty oil in an automatic causes jerking, slipping and eventually mechatronic damage whose repair can exceed half the car's value.
Power steering fluid in vehicles that still use a hydraulic power steering pump is replaced every 80,000 to 100,000 km or when it turns dark and murky. Many manufacturers do not list an interval because they treat it as a lifetime fill, but in practice, changing the fluid prevents wear on the pump and the steering rack.
Why the Service Book Is Not Enough
Service book intervals are written for marketing, not for longevity. The manufacturer wants the total cost of ownership during the warranty period to look low because that sells cars. Once the warranty expires, that incentive disappears.
Our local reality is a textbook example of "severe service" conditions that every owner's manual mentions but few drivers apply to themselves. Short city trips where the engine never fully warms up, dusty local roads, inconsistent fuel quality, summers above 35 degrees and winters below -10, all of that shortens change intervals. If this description fits your driving, stick to the lower end of the ranges we listed. For a breakdown of exactly what goes into a basic service and how to tell when it is due, see our guide.
Track Your Intervals, Avoid Surprises
The best way to never miss a change is simple: keep a record. Write down the date and mileage of every replacement. When you visit our workshop, we will review what is due and what can wait.
If it is time for a full check of all fluids and filters, see what our major service includes. To book an appointment, reach out through our booking page or contact page.