Although an article from Oregon- I believe E10 is now mandated in most if not all states.

Cut and paste:

The Industry Update
For the weeks of March 3-10, 2008

Called E10 (10% ethanol fuel), all fuel sold in Oregon will be a mix of gasoline and E10 phased in by these dates: January 15, 2008, for northwest Oregon; April 15 for mid-state; and September 16 for eastern Oregon. This requirement will remain in effect on a year-round basis. Each year, Oregon blends nearly 14 million gallons of ethanol into its annual gasoline consumption of 1.5 billion gallons. Over 99% of fuel ethanol in the U.S. is consumed as E10, a 10% blend with gasoline which can be used in any gasoline vehicle.

As with any new fuel, precautions are necessary to keep a car running at an optimum level. Since E10 fuel absorbs water, and can absorb 50 times more water than conventional non-alcohol gasoline, phase separation happens when only 0.5% water or 3.8 teaspoons water per gallon of fuel is absorbed. When phase separation occurs, octane can drop as much as 3 points in the fuel. To prevent phase separation, maintain a sealed fuel tank, and avoid the gas tank from coming in to unnecessary contact with water. Customers should also buy gasoline with a higher octane to be certain that the engine will be running on the minimum octane necessary for good performance. While some may disagree, unless you are 100% sure the fuel is good, a higher octane can add extra protection if the gas suddenly enters a “phase separated” state.

The shelf life of ethanol blend fuels is much lower because of its water absorbing and corrosive qualities, so replacing gasoline in the tank every 2-4 weeks is recommended. Since the amount of ethanol blended in at the pumps is not closely monitored, the most effective precaution you can take with alcohol blend fuels (E10 and E85) is to make sure you only run your engine on clean, new, fresh fuel. Also, ethanol is a solvent and a cleaner, and can dissolve engine parts, dry out hoses, remove lubrication, and more. Engine seals and hoses shrink, swell or lose strength when exposed to ethanol reformulated gasoline. Other chemicals in fuels used in the past did not have this happen.

Most new engines (1997 on) are designed to tolerate 10% or lower ethanol in gasoline, and most new cars have oxygenated systems. However, ethanol can cause “knocking” in an engine. It also can be hard on all systems that gage off the fuel mixture. Keeping engines tuned and following the manufacturer’s recommended maintenance schedule are important deterrents for engine problems.

Before your next fill up remember- "The shelf life of ethanol blend fuels is much lower because of its water absorbing and corrosive qualities, so replacing gasoline in the tank every 2-4 weeks is recommended.". Not much of issue with your gas tank as I am sure most fill up once a week- BUT- do not assume the gas station has fresh gas!!! Look for a station that sells a bunch of gas- that way you are reasonably assured that you are getting fresh gas.

I think the jury is still out as to any long term effects E 10 might have on your engine. I guess we will find out .

 

E10 had been around since the late 70's. It's was called Gasohol. I ran it for years in my cars and bike with no problems. It's when you get into the 20% and up range that you start having problems.

 

Yep. I am well aware of that. There are many who are concerned about the long term effects on modern vehicles. So far, many are seeing a reduction in gas mileage with E10, some people are complaining of rough running engines and pinging. Goggle what it is doing to boats!

State and Federal mandated oxygenated 'boutique gas' blends do not have a great track record. For example, now banned, MTBE caused cars to run terrible in hot weather and contaminated groundwater.

 

Oh yeah, they used to make MTBE right across the street from where I work now. Nasty stuff, only very special (read expensive) seals would handle that stuff and they put it in motor fuel? That was just nutz. Using alcohol in boat fuel is just nutz also.

 

Ethanol is known to cause damage to natural rubbers- which may be a factor for those who have mods where natural rubber is used and comes into contact with the rubber. Good catch Wingsprint!!