Using ethanol free gas.

Turtle n Peeps wrote:
E free gas will give you about 4 to 5% difference in mileage.

If anybody tells you appreciably more their math is wrong or their testing is flawed.

E gas will always give you more power because of the O2 and cooling effect it give your engine.

Totally agree! How can eliminating the 10% alcohol give you an additional 6 mpg on the highway..I'm gonna have to throw the BS flag on that one.

B.O.

CavemanCharlie wrote:
All the gas in MN is E10. No matter what it says on the pump. If it says otherwise it's just to make you feel better. If you think you are getting better mileage using non-ethanol gas around here then you are just imagining it.

It's like someone taking a drug that they say makes them feel better. When in reality the doctor just gave them a placebo.

Where my seasonal site is at in MN they sell boat gas that is E-0.

CavemanCharlie wrote:
All the gas in MN is E10. No matter what it says on the pump. If it says otherwise it's just to make you feel better. If you think you are getting better mileage using non-ethanol gas around here then you are just imagining it.

It's like someone taking a drug that they say makes them feel better. When in reality the doctor just gave them a placebo.

Are you sure?

Pure Gas Website Minnesota Page

This website lists 469 gas stations in Minnesota that sell ethanol-free gas.

All the gas in MN is E10. No matter what it says on the pump. If it says otherwise it's just to make you feel better. If you think you are getting better mileage using non-ethanol gas around here then you are just imagining it.

It's like someone taking a drug that they say makes them feel better. When in reality the doctor just gave them a placebo.

I'm not sure where you live, your profile doesn't show it, but in a lot of areas the reg's are such that they sell enough volume of regular and mid-grade gasolines being E10 that they cam sell premium as E0.

Since vehicles that require premium fuel are often in a class that doesn't tolerate fuel degradation well they try to keep it ethanol-free wherever possible.

JaxDad wrote:

westend wrote:
So let me understand this, there were people who claimed that replacing 10% of their gas with Ethanol resulted in a 15% loss in mileage? This must have been a user calibrated event.

My only real experiment with alcohol and different fuels was driving a late model minivan. I rented this van and used E85 for a few tankfuls (maybe 5). I noticed a 10% loss in mileage compared to E10.

The big problem is water.

Before the transition to Ethanol the oxygenation was handled by the addition of MTBE to gasoline, this mixture does not absorb water in any material amount.

Ethanol on the other hand mixes quite readily with water and is in fact hygroscopic, it very aggressively absorbs water and holds it in suspension until it's saturated and just cannot absorb any more.

Despite very prevalent myths to the contrary, phase separation occurs very quickly under the right conditions, and even under just typical atmospheric conditions occurs in 90 days on average. This is caused by the ethanol just absorbing the humidity out of the air and condensation. If there is actual water present, like in the bottom of a storage tank, the ethanol quickly absorbs it.

At just 0.5% water entrainment reaches the point where the E10 mixture is no longer able to hold the water in solution. At this point the water-laden ethanol starts to fall out of solution and settle down out of the mixture. You would then have a large top layer of nearly pure gasoline, and a much smaller layer of very water-laden ethanol below that, then finally a smaller layer of pure water at the very bottom.

As the ethanol falls out the gasoline loses an important source (the ethanol) of it's octane. If you had this happen, 87 octane fuel would drop to approx. 84 octane.

So now you have a car running on non-oxygenated 84 octane fuel until it gets down to the very wet straight ethanol at the bottom of the tank.

Now this is an extreme example, but it only takes a little water to significantly affect performance.

Well that makes a lot of sense, I had not thought about the Octane level being modified.

On the other hand, I have run Premium in some of my vehicles (instead of Regular) and the mileage is just a bit better. Is Ethanol the only Octane booster in E10 gas?

westend wrote:
So let me understand this, there were people who claimed that replacing 10% of their gas with Ethanol resulted in a 15% loss in mileage? This must have been a user calibrated event.

My only real experiment with alcohol and different fuels was driving a late model minivan. I rented this van and used E85 for a few tankfuls (maybe 5). I noticed a 10% loss in mileage compared to E10.

The big problem is water.

Before the transition to Ethanol the oxygenation was handled by the addition of MTBE to gasoline, this mixture does not absorb water in any material amount.

Ethanol on the other hand mixes quite readily with water and is in fact hygroscopic, it very aggressively absorbs water and holds it in suspension until it's saturated and just cannot absorb any more.

Despite very prevalent myths to the contrary, phase separation occurs very quickly under the right conditions, and even under just typical atmospheric conditions occurs in 90 days on average. This is caused by the ethanol just absorbing the humidity out of the air and condensation. If there is actual water present, like in the bottom of a storage tank, the ethanol quickly absorbs it.

At just 0.5% water entrainment reaches the point where the E10 mixture is no longer able to hold the water in solution. At this point the water-laden ethanol starts to fall out of solution and settle down out of the mixture. You would then have a large top layer of nearly pure gasoline, and a much smaller layer of very water-laden ethanol below that, then finally a smaller layer of pure water at the very bottom.

As the ethanol falls out the gasoline loses an important source (the ethanol) of it's octane. If you had this happen, 87 octane fuel would drop to approx. 84 octane.

So now you have a car running on non-oxygenated 84 octane fuel until it gets down to the very wet straight ethanol at the bottom of the tank.

Now this is an extreme example, but it only takes a little water to significantly affect performance.

JaxDad wrote:

westend wrote:
No one is losing 10% in mileage by using an E10 gas blend.

I have no reason to doubt the OP's results but some of his mileage differences may be due to the intrinsic construction of the engine and it's fuel management accessories and not absolutely due to the addition of alcohol.

Funny that. Gasbuddy.com held a poll on users mileage loses due to using E10 fuel. The largest group responding said they lost between 5% and 10%, the second largest group said they lost between 10% and 15%.

Then from the website of a little magazine called Road & Track I find ".... switch to E10 (gasoline cut 10 percent with ethanol), your mileage will drop. The big question is by how much. The Environmental Protection Agency says E10 lowers mileage approximately 3 percent, which would drop your mileage from 19.6 to 19.0 mpg. Instead you're citing a drop between 10.2 and 15.9 percent, which, while similar to some E10-induced losses we've heard of, does seem large. We typically hear of mileage drops in the 6- to nearly 10-percent range..."

So let me understand this, there were people who claimed that replacing 10% of their gas with Ethanol resulted in a 15% loss in mileage? This must have been a user calibrated event.

My only real experiment with alcohol and different fuels was driving a late model minivan. I rented this van and used E85 for a few tankfuls (maybe 5). I noticed a 10% loss in mileage compared to E10.

westend wrote:
No one is losing 10% in mileage by using an E10 gas blend.

I have no reason to doubt the OP's results but some of his mileage differences may be due to the intrinsic construction of the engine and it's fuel management accessories and not absolutely due to the addition of alcohol.

Funny that. Gasbuddy.com held a poll on users mileage loses due to using E10 fuel. The largest group responding said they lost between 5% and 10%, the second largest group said they lost between 10% and 15%.

Then from the website of a little magazine called Road & Track I find ".... switch to E10 (gasoline cut 10 percent with ethanol), your mileage will drop. The big question is by how much. The Environmental Protection Agency says E10 lowers mileage approximately 3 percent, which would drop your mileage from 19.6 to 19.0 mpg. Instead you're citing a drop between 10.2 and 15.9 percent, which, while similar to some E10-induced losses we've heard of, does seem large. We typically hear of mileage drops in the 6- to nearly 10-percent range..."

westend wrote:
Yup, valid all the way.
I mentioned the last about the engine so that folks don't go and buy a tank full of non-E gas, thinking they are going to boost their mileage as the OP was able to do.

Got it. Makes sense to me. With an engine designed to run E10, the mileage difference should be close to the BTU difference.