For a car in taxi service, I can see that. As they spend a lot of time idling and in city traffic. But 30k miles in one year - I would expect those to be mostl

For a car in taxi service, I can see that. As they spend a lot of time idling and in city traffic. But 30k miles in one year - I would expect those to be mostly highway miles and those are easier on engines -- so you can stretch the oil change intervals by 25% or more.