I have a 2014 Mercury 150 Pro XS. Everything I have read says to run 87 octane. A gas station has opened in my area that sells non-ethanol 89 octane. So which is better for my motor, 87 octane with 10% ethanol or 89 octane with no ethanol? Another concern is that it is a single pump off to the side. How much do they sell and how long have they had it.