I don't go anywhere near a Shell gas station! A few years ago, Shell faced a huge class action lawsuit in Canada because they were putting something in their gas that caused damage to a lot of vehicles. I guess they claimed it was an anti-freeze additive of some sort which actually coated the inside of the gas tank among other engine components with a gel like substance. It also coated the fuel tank sensor - which showed the vehicle as 'empty' even though the tank was full. Chrysler among other manufacturers paid for repairs and replacement of fuel tank sensors, fuel filters, etc. to hundreds of affected vehicles - which they in turn sued Shell for. We had two vehicles in the family that were affected (not BMW's) and I have stayed away from Shell ever since!