I looked at an 840 the other day and the seller told me that he had had to fit new sets of catalytic converters. He said that BMW had told him that they die off because of the quality of the petrol.
I was suprised by this...
If this is true, is it because it's a car that's ~ 10 years old (although only ~ 50K on the clock) and petrol from yesteryear didn't have all the modern additives to keep the engine and cats clean?
So...this brings me onto a related question. What unleaded fuel should one run an 840 on? The normal or the "super" unleaded fuel?
Thanks everyone in advance
Griff