If your fuel pump doesn't have separate hoses for all the grades of fuel, you are getting some fuel of the grade the prior users selected.
Essentially you pump the fuel left in the hose from the prior user. If that was E85, you may be your one gallon can may end up with 30% ethanol
See this video
Essentially you pump the fuel left in the hose from the prior user. If that was E85, you may be your one gallon can may end up with 30% ethanol
See this video