BG products are pretty good things a lot of BMW dealers sell there stuff. Pro's of using it, keeps the fuel system clean from pump to intake valves. Helps remove any moisture build up, increases octane slightly during cleaning. Con's really are not that many. If used to often can dry out seals since it does have a ethyl comment in it. Here is a good review of what it does and the good and bad. https://www.helpful.reviews/en/product/1/bg44k-fuel-system-cleaner-review
