Hello, if buying mid grade gas and the pump only one hose for all the grades how much of the last grade to you get? All the stations around here only uses one hose, so if I want mid grade and the person before me got reg do I end up getting what is in the hose before I get what I wanted? I buy only one gal at once most of the time so do I get part in the reg grade. Or does the hose gets pumped back when it is shut off. If don't I feel like i'm getting what I pay for. Has this ever been checked? Thanks!