The most common question in the workshop: how often should I change the oil? The honest answer is that there is no single figure for every car. Toyota itself publishes two intervals: a normal one and a 'severe operating conditions' one.
The catch is that most driving in Cairo and Giza falls under severe conditions: constant traffic, frequent stop-start, high summer heat and dust. That means the shorter interval applies to you, not the ideal one quoted in adverts.
A practical rule: mineral oil every 5,000–7,000 km, semi-synthetic every 8,000–10,000 km, fully synthetic every 10,000–15,000 km — with a monthly level check you do yourself.
And something more important than the number: the oil's colour and level. If the oil turns thick and black, or the level drops between changes, that points to consumption or a leak that needs inspection — not just a change.

