Originally Posted by scottrh
I have purchased a 2013 X3 2l diesel. Recently I counted the number of stop-starts while travelling through town - about 20 times over a distance of less than 10km, mainly due to poorly synchronised traffic lights. As I am concerned that this is excessive, could BMW please assure me (and other members) that the starter motor assembly has been designed for so many starts over such a short travel distance on a daily basis.
As I've intimated on other threads on this subject it is not the starter which would incur the highest cost as a result of excessive wear. The gearbox would need to be removed to replace the fly wheel (drive plate for auto) ring gear. This would certainly be very costly and far outcost any benefits gained on fuel economy. Thats why BMW print a disclaimer on the usage af this system and state that it may increase wear on certain (unnamed) components. I suppose deciding whether or not to use this system will depend on how long you intend keeping the car. Wear on these components under traditional use is not significant but that is based on historical use i.e. start the car at beginning of journey and stop at destination. As you say this stop start sequence of engine starts can be easily as much as twenty times during a single journey. I have no idea how long it will take before excessive wear causes an engine start malfunction and subsequently costly repairs. Time will tell but you can bet that BMW will not replace under warranty as it will no doubt be regarded as "wear and tear" and owners referred to the handbook disclaimer.