https://www.bar.ca.gov/pubwebquery/station/stationlist.aspx
2004 Mazda 6 3.0L engine https://www.youtube.com/watch?v=Tw-8haU2syg
2007 Mazda 6 https://www.youtube.com/watch?v=c0tSPM_DadE
Suggestion from First Auto: Topping off can overflow the carbon cannister and can cause more problems.