Is it true that hi-test (91-94 octane) has more issues with fuel/ethanol separation at the gas station due to low sales? When buying hi-test for high compression motorcycle some say that the fuel separation causes running issues. Also for winter storage. Some say buy high turnover regular fuel and add booster instead. True/False?

The only thing I buy for my small engines is the non-oxygenated fuel which at my station is the high test for off road equipment. That’s all I would use in a cycle.

So rather than buying fuel with the booster in it you are buying buster and then adding it. I don’t se the advantage.

If you are storing a vehicle over winter you should use a fuel stabilizer.  I have some in my Honda BIke right now.  

It is always best to buy fuel from a source that has a high volume.  Frankly I don't think you should have any problem finding one.

High turnover is good, but what are we talking about? You should certainly avoid a station that gets one tanker in every three months, especially if buying before winterizing. But there is a downside to the quick turnover gas stations as well. Pumping fuel into the underground tanks stirs up sediment that, if you buy gas soon after a tanker has arrived, ends up in your tank. There is no filtration between the underground tank and you gas tank.
So go to a gas station that gets a tanker in once per week, minimum, and if you see the tanker truck delivering fuel, put off getting gas for a few hours.

High turn-around gasoline has less chance of the phase seperation when it contains ethanol.

To prevent phase seperation of the gasoline and ethanol/moisture while in storage use a product that contains isopropyl alcohol. This prevents the phase seperation of the ethanol/moisture out of the gasoline. Seafoam Engine Tune-Up contains isopropyl alcohol and is formulated for this purpose. Follow the directions on the container.


Seafoam: That sounds like a good idea. I do mix winterizer in my fuel for my bike. I had just heard about excessive ethanol separation issues. As far as fuel turn-over, the story is that due to so much less high octane fuel being sold, it sits longer and may separate in the tanks and be a concern. One more question: assuming that the fuel in a underground tank pumps from the bottom, would you receive at the pump a higher concentration of either ethanol or premium fuel?