Those extremely long intervals will only work for cars that travel long distances, where the engine has a chance to warm-up and burn off any residual gasoline that gets in the oil during cold starts. If said car spends most of its life in a city, doing short trips, the oil gets rapidly dilluted and loses the ability to lubricate the engine properly.
Most modern cars will take all this into account when trying to determine when the next oil change is due. Also, manufacturers nowadays usually specify shorter intervals (6 months or 7500km) for modern direct injection engines that only drive in a city.
Those extremely long intervals will only work for cars that travel long distances, where the engine has a chance to warm-up and burn off any residual gasoline that gets in the oil during cold starts. If said car spends most of its life in a city, doing short trips, the oil gets rapidly dilluted and loses the ability to lubricate the engine properly.
Most modern cars will take all this into account when trying to determine when the next oil change is due. Also, manufacturers nowadays usually specify shorter intervals (6 months or 7500km) for modern direct injection engines that only drive in a city.