Know that that my 05 Heritage is good to go on 10% ethanol but was concerned about phase separation of the fuel. I understand that ethanol is basically alcohol. Since the ethanol will attract water if gas sets in tank there is a danger of fuel attracting excess water. Also understand some of the fuel additives contain alcohol. I run a tank of gas about every 5-10 days. Should I be using an ethanol treatment? Thanks.

 

I've never heard that ethanol would attract water. I do know that grain alcohol will dissipate water in a fuel tank.

 

Ethanol, which is by the way grain alcohol, will absorb moisture from the air in an open fuel system. It will also aid in dissolving water in gasoline, but only to a point. This is true with other alcohols also, such as methanol and isopropyl alcohol.

Here's a pretty good article from a British car website;
http://www.mossmotors.com/SiteGraphi...s/Ethanol.html

 

If you are going through a tank in less than a week you will be fine on the seaparation issue. Still Ethanol can corrode older fuel systems and will give you less MPG in all cases. I just avoid the stuff whenever I can. If you are worried about leaving it in there longer than a few weeks, especially if it were to just be sitting, add Sea Foam to the tank to help keep it all together.

 

Ethanol in fuel has a tendency to absorb water and separate from the gasoline, sinking to the bottom of the gas tank, where it quickly degrades and creates gum, varnish and other insoluble debris that can plug fuel flow passages and negatively affect engine performance. When this ethanol/water mixture is pulled
into the engine, it creates a lean burn situation that increases combustion chamber temperatures and can lead to engine damage.
As mentioned, if running thru the fuel quickly it may not be as big of a concern. I can avoid it my state but I know there are some that can't. Treating periodically may not be a bad idea.
Here's what I use: Quickshot

 

There are no fuel stabilizers which address ethanol--it's marketing hype.

In "pure" gasoline (which isn't actually pure, but I use the term to mean "free of ethanol") only a little bit of water can be held in suspension before it phase separates and settles to the bottom. Yes, this means that without ethanol phase separation happens earlier. Of course, water has to actually get into your tank for this to be a problem. It can enter through the day/night heat/cool cycle as moisture in the air works its way through the vent tube, but it would literally take years under normal circumstances for enough water to build up in order to cause a problem.

With ethanol in your fuel, things change. The ethanol can absorb significantly more water, so it takes longer to phase separate. It's more a problem on boats where water is far more likely to make its way into the fuel tank. Once it finally does separate, the water and ethanol settle to the bottom, which lowers the octane of the fuel above. But, again, it would take years for water vapor to build up via the vent tube. The ethanol can only absorb the moisture available to it.

What fuel stabilizers do is fight oxidation. Gas goes bad typically via a combination of oxidation and volatility (the more volatile components evaporate).

So, really, it's only a problem if you have a leak on a bike which sits outside in the rain and allows significantly quantities of water in, or one which sits without being ridden for years at a time.

 

I work on small engines, mowers, snowblowers, chainsaws, etc. Only 2stroke engines have a problem with the small amount of water/ethanol mixture that does separate from the fuel itself. That is because of the two strokes need for oil in the mix. In the equipment that requires fuel/oil mix the pickup is in the bottom of the tank and that is where the separated water/ethanol ends up. Simply shaking the unit before startup, (if it has been sitting for awhile) will put the water/ethanol back in suspension and relieve the problem. The separation itself creates no long term problem for four stroke engines because necessary lubrication is not part of the fuel. The two real problems are the fact that ethanol fuels degrade the hoses used in the fuel system, faster than straight gasoline, a reason why I change out fuel lines for teflon when it becomes necessary, I do not know if these are made large enough for mc or autos. The second problem is that additives in ethanol tend to begin deteriorate the fuel faster and since fuel for lawn and garden equipment tends to sit for longer periods than does fuel I recommend to friends and customers that they use a stabilizer each time they fill the gas can for their lawn equipment. I recommend star brites ALL in One or Seafoam as they are also fuel system cleaners. I even put them in the bikes a couple times a year and right before winter storage. To answer the ops question if you go thru a tank in less than a month don't worry about either issue, I would say toss in a little seafoam now and again. I truely believe it helps and it won't hurt. IMHO

 

I said that couple yrs ago in here, several others claimed they getting better fuel mileage.. I know I haven't, I loose around 10% every time I use it.

 

You can buy ethanol free gas at any marine or RV dealer

 

+1 Great post!

I'm sure there is a place for additives, but as with many other products the manufacturers feed on fear and paranoia.