Not a biggie, but when you "top up" with premium, say half a gallon or so. What you get out of the hose is Lo Grade from the last customer.... until your Premium selection goes through the pump, meter, hose and out the nozzle. The next guy gets the Premium that you paid for. In the good old days, there was a separate hose for premium, and you got what you paid for. When I'm climbing a long grade and my Softail starts to ping, I sometimes wonder if it was that mix of Lo grade that i just bought.