Re: Chances are the gas will not contain a full 10% ethanol. My info is at least here in the USA...

So, living overseas, Esso gas is subsidized by the DOD to roughly equate prices in the states. Being half the local rate, it's pretty much prohibitive going to other brands. Esso here is slowly but surely phasing out super and replacing with E10.

I have no experience with it, but need to know what to expect in my 01 S and also in my 07 BMW X5. I had heard that mileage is atrocious. Any experience?

refineries stopped short of the full 10% deciding on around 7% to 8%.

No one can say for sure -- perhaps where you are the the refineries will on their own go for the full 10% (or have to be *law*) or they might try a different additive package the is not as good as keeping the ethanol/gasoline blended -- but based on my experiences with running 'E10' here (and gallons and gallons of it) I don't think you're 01 S will have any problems.

Ethanol contains less energy and it of course displaces gasoline that contains more energy so distance traveled per unit of fuel will be less, all other things being equal. Yet another factor is ethanol carries oxygen and releases this during combustion. The O2 sensors pick this up and the engine controller thinking the mixture is too lean (too much oxygen) adds more fuel. (Ethanol and other oxygen carriers were intended for carburated engines which tend to run on the rich side, so the extra oxygen would be present to help combustion. But since all modern cars are fuel injected and use oxygen sensors to monitor the amount of oxygen in the combustion exhaust gases and the amount of oxygen in the converter exhaust gases fuel injected engines do not run rich. They in fact run a bit on the lean side, cause the converters are most efficent and have a very narrow window of efficiency with the engine being fed an air:fuel ratio of 14.7:1.

Regardless, the impact to fuel economy is not that bad. Maybe on the order of 2% to 3% unless you do get real 'E10' gasoline then fuel economy might suffer a larger percentage drop.

Buy from a busy station to always get the freshest gasoline. If you're going to leave the car sit long periods of time unused investigate a gasoline additive that helps prevent gasoline break down (gas going stale) and delays the stratification of the gas/ethanol blend.

Lastly, IIRC Porsche does say in the owners manual that if running an ethanol blend of gas causes engine problems, go to a gas that has less ethanol or don't run ethanol at all. But of course in many areas that's impossible since only ethanol/gas is offered.

Sincerely,

MarcW.

In the US, check with www.pure-gas.org to find a no-ethanol station in your area.

I find more problems with small engines like chain saws and mowers than in my cars. They tend to sit around longer between uses.

Thanks. Sounds like you have done somw homework on the topic!

i gather it can create issues with the fuel system, agree with all MarcW said on performance, and it is only make food prices more expensive for poor people, so wouldnt never buy it anyway