In brief: about traffic jams...

If your car spends most of its life in city driving, commuting to work and back — the oil change should be done more often than the manufacturer recommends.

The thing is, the oil in an engine gets contaminated and oxidises over time. It oxidises in traffic jams and at high revs, and dirt gets into it from dusty air and with poor fuel. So the “harder” the conditions an engine works in, the more often you need to change the oil.