Variable service interval algorithms

[oniznorb]

Does anybody know the detail of the algorithms used for variable service intervals?

Are they very simple ( like just counting total engine revolutions ) or do they tale nput from amny sensors?

[GavinPearson]

A diesel with regenerating DPF oil change interval is hideously complicated. I have direct experience of this and I was astounded by the complexity and cost to do the work.

Petrol engined versions are a lot simpler, but still by many standards complex if you are trying to do the job properly.

Why?

[oniznorb]

Why?

It would be interesting to compare my driving style with the main parameters used in the algorithm to see if I can increase the interval. I would expect that a smooth, sympathetic and efficient driving style should be rewarded with a long interval, but the algorithm may not do this.

[GavinPearson]

For a petrol engine it would be based on the number of cold starts, time idling, time at high revs, time at medium rpm.

Avoid cold starts, never idle, never use high revs and your oil life will be maximised for that particular engine.

However that isn't terribly practical so if you are worried about making your car last a long time change the oil a lot more often.