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[QUOTE=x99;9847727]The new BMW have the Condition Based System (CBS). It checks your oil quality and driving condition.
As noted in my previous post, the CBS computes the mileage to the next oil change based on:
1. Total miles driven.
2. Number of cold start and miles driven before the engine is fully warmed up.
(miles driven when “cold" are given a much higher "weight" then miles driven when warm)
3. Percentage of miles driven at high rpm (rpm trigger value based on engine temp.) (miles driven at high rpm, typically over 4K for the petrol engines and 3K for the diesels, are given a much higher weight than low rpm miles)
There are oil level and oil temperature sensors. There is NO "oil quality" sensor.
The CBS is an algorithm that, at best, estimates the condition of the oil based on knowledge of the conditions the vehicle has been subjected to. Actually measuring the oil "quality" in any meaningful way requires testing methods beyond what would be practical to install on a moving vehicle.
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