Originally Posted by scotta2
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.
I totally agree. The stress on numerous known and unknown parts is not worth the small saving on fuel. I guess if you plan on keeping the car for just a couple of years it might be OK.
Regardless, the resulting shudder (35d) when starting it and delay (even if short) when taking off is irritating and in my opinion could be unsafe. As a result I shut it off immediately upon start-up.
In the States you have the option of deactivating it but here in Europe BMW says we are stuck with it.