What sorts of intervals are recommended for changing motor oil?
The standard criteria for changing motor oil are distance and time. Generally, 3-5,000km or 6 months (whichever is first) is the interval normally used in Japan. Although the actual trend for oil change intervals as specified by the manufacturers is trending towards 10-15,000km plus (or once a year), to really keep an engine consistently working in prime condition people often replace their oil at shorter intervals. Furthermore, for vehicles that have higher power output, turbo cars and diesel cars, or those on severe drive cycles, short change cycles are recommended depending upon conditions of use. It may seem strange, but using your car for short trips only (such as a quick 10 minute or so visit to the local supermarket) means that the motor oil does not heat sufficiently and water and fuel can accumulate in the engine, leading to a build-up of sludge and rust, and causing wear. So, in actual fact, the belief that the car has not covered much distance and therefore changing the oil
