Originally Posted By: Nyogtha
While all US gasoline is now ultra-low sulfur, it's a 10 ppmw average rather than per gallon limit. It can be up to 80 ppmw S at the refinery gate, and a little above that at the terminal & retail station to allow for minor cross-contamination in transit. Overcontrol generates bankable & tradeable gasoline sulfur credits.
Don't bank on every gasoline purchase at the pump being 10ppmw S or less.
I'm glad you mentioned this.
However, if the average is 10ppm, over a year, unless I'm really unlucky, shouldn't the gas I consume have averaged 10ppm?
Also, if some gas can be 80ppm, then doesn't that mean, for example, that for each unit of gas at 80ppm, there will need to be 14 units at 5ppm in order to average 10ppm?