I wanted to talk about phase separation, My wifes car today decided to run rough and wanted to stall. No codes were thrown and ran better later. This time of year with the colder mornings and ethanol gas sold everywhere now there is going to be a lot of problems that people are not used to. Here are a few tips that I use.

1. Keep fuel tank full. Moisture from the air will condensed on the side of tank and fall into the gas. Water will separate at 50-60 degrees depending on water content.

2. People use Heet in the yellow bottle especially down south, Not needed ethanol in the gas does the same thing. If you still want to use Heet use the red bottle Iso-heet its better for the gas and motor. Heet in the yellow bottle is Methanol and is very corrosive to aluminium motors and sensors, was made for iron blocks along time ago. Iso-heet is safe. Ethanol is corrosive too but no where near as bad as methanol.

My son took my wifes car and put a few gallons of premium gas in and the problem is fixed. When gas separates the gas left over is lower octane so adding a few gallons of premium raises the octane back to 87 or higher. I did not have this problem this morning because I use premium. Premium gas holds in suspension more water so if phase separation happens the octane level will still be higher that 87.

I am not pushing premium but a few gallons every once in a while will help. I plan on using regular over the winter because of the cold, higher octane is not needed.

If any one has other ideas post them here.

 

Where did you read that premium holds more water in solution? Intuitively I think it would be the same as regular.

An interesting footnote is that gasoline with ethanol is less likely to experience phase separation because it does hold more water in solution.

link.

I'm not going to worry about water in my gas. Never have. Just don't buy from seedy side street sellers of questionable fuel. Never ran premium either except in a car that recommends or requires it.

 

Get a bicycle and you wouldn't have to buy gasoline.

 

I keep a bicycle in the bed of my truck because it uses so much gasoline I'm never sure if I can make it from the house to the nearest station. Shameless thread-jack and i apologize

 

I take it you don't have anything to support yet another Silver Bullet endorsement for the use of premium fuel in an economy car.

 

My wife uses your regular in her car and has 4000 miles and is happy getting 25 mpg on it, so if premium prevents the effects of phase separation and the trip to a dealer so be it. Keep in mind I get 40 plus in the same kind of car. I drove city today to pick up my son and still got 40 plus, I actually drove the car hard and got better mileage then highway using premium.

 

reference, please? (I googled but my searches failed to find any).

It's ironic that you're unable to convince your wife of the benefits of premium gas. I finally got mine to stop putting premium in her 98 Camry, but she still insists on changing the oil every 3,000 miles (the dealer said to!).

 

Here is info on phase separation

Fuel School: Phase Separation in Ethanol Blended Gasoline
What is ?phase separation??
Phase Separation in Gasoline

Keep in mind that winter blends dont come out until Oct 15, so summer gas can separate in cooler temp than normal.

 

uh thanks, but that says nothing about premium fuel preventing phase separation.

edit: or preventing the "effects" of phase separation. Once your gas has separated you've got a problem that requires emptying the tank. Adding more fuel, premium or otherwise, just postpones the problem; it's unlikely the water and/or ethanol will go back into solution with the gasoline leaving a layer of potentially damaging liquid at the bottom of your tank.

If you're saying ethanol contributes to the likelihood of phase separation, the link I provided, as well as your own opening post (mentions HEET) state the opposite.

 

She knows when I run premium in her cars, I told her not too. I wanted to compare the two cars until this problem came up. I go once a year on oil change in her van sometimes longer. So what are you going to do when your Camry starts acting up,blame it on premium? All I am saying is there is a purpose for premium and many cars will run fine on regular, but if you add up all the extra maintenance and other related cost is it worth it to run regular.

 

Nope, she switched to regular in 2008 when gas prices were so high. Not noticing any difference finally convinced her that premium was a waste of money. I'd like to think it was my use of logic and facts, but well, you know how that goes.

What extra maintenance and related costs using regular? You have yet to show any...

 

There was only a few gallons of gas and premium hold more water in suspension.
Here is a link that explain the lowering of octane in phase separation
Gasoline Octane and E10 Ethanol Blend Fuels

As far as heet, Ive used in the past in my older cars before I started to use premium. If heet is so good thats why they change formula to Iso heet.

Here is a short write up on isopropyl alcohol Iso heet
Methanol-gasoline blends: blending agents to prevent phase separation
David W. Ostena and Nancy J. Sell*
aUniversity of Washington, Seattle USA
*University of Wisconsin-Green Bay, Green Bay, WI 54302, USA
Received 29 December 1981; revised 10 August 1982. Available online 12 August 2003.
Abstract
The use of methanol-gasoline blends as automotive fuel is limited, in part, by phase separation at low temperatures. The separation temperature of these mixtures can be adjusted by varying the percentage of blending agent present. Two blending agents were considered in this study, tertiary butyl alcohol and isopropyl alcohol. Both were found to significantly lower the separation temperature, although, isopropyl alcohol is more effective, possibly due to its greater ability to form hydrogen bonds. Correlation equations were derived relating the percentage compositions and the separation temperature.

 

fuel injector cleaning auto maintenance | automobile maintenance | fuel injection service | gas prices

 

If your argument, as this site suggests, is that premium fuel is premium because they add more ethanol than regular to raise the octane rating thus making its ability to hold water in solution greater, it sorta lays waste to all your other premium fuel claims about added power and efficiency. You have argued profusely on this point, Mr. Bullet. You can't have it both ways.

 

Premium gasoline may have more detergents than regular. Can you provide any reference that supports this claim? Something besides the manufacturers' claims would be helpful.

Added detergents (if they are really more than regular fuels) are not what make premium fuel "premium." The premium aspect is additives to raise the octane rating. In the case of your site above this is ethanol, which lowers energy content and will have a negative effect on fuel efficiency.

I advocate buying fuel from a station that is less likely to have phase separation (i.e. water in their storage tanks). The amount of traffic the station receives and its general maintenance (i.e. well maintained pumps, hoses, nozzles, grounds and general age) is an indicator. Price and grade at the station have little to do with it. Premium fuel, by virtue of its price may actually have sat in the station's storage tanks longer making it more likely to have problems!

If you think you have phase separation, water or ethanol, in your tank, the best thing to do is take it to a mechanic and have the tank drained and filled with fresh clean gasoline.

 

The law says 3.5 percent oxygen which is 10 percent ethanol. Most gas is 8 percent ethanol.
Premium gas has etbe,butanols and other alcohols which have a lower oxygen content so more is needed. Cheap gas has more ethanol and most premiums are considered ethanol free Ethanol Free Premium Coalition

 

Draining the tank and changing fuel filter, Tow, and clean gas cost more than premium would in your cars life time.
I buy from high traffic gas stations too. Premium dont cost me more, I get better mileage and what you dont understand is if you get 24 miles more out of a tank, its the cost difference of the two fuels.

Shell V-Power® - United States

Fuels | Amoco UltimateŽ with Invigorate

http://www.bp.com/sectiongenericarti...tentId=7009025 Bp in UK. notice that they say 28 miles further. Its the same gas here.

 

What law are you talking about? It's a regional requirement to abide by federal clean air standards controlled by each state. Atlanta has different rules than Savannah.

The link you provided is an individual's call to "petition" for ethanol free premium gasoline. It doesn't state that premium is ethanol free; quite the opposite.

If premium were ethanol free, then its ability to retain water in solution is less than regular (assuming regular has ethanol).

Premium may have more ethanol than regular (as pointed out in the link you provided above) resulting in less energy.

The octane rating of premium fuel is the only difference; the fuel's tendency to resist knock. Not energy. Not its ability to hold water in solution.

Premium fuel doesn't prevent or cure phase separation. Your links don't support this.

The links for Shell and BP are nice. They may actually have more detergents in their premium fuel than they do in their regular fuel, however they don't actually state this. All they compare their premium brands with is with the federally mandated minimum standard. No where do they compare with their own brands of regular fuel in terms of detergents. If "top tier" is to be believed (another dubious marketing effort created by Quick Trip) their regular gasoline adheres to the same standard.

 

Did you notice this is an advertisement by the seller?

Can take you 28 miles further than what? Not putting fuel in your car? This is marketing nonsense. It's a meaningless statement.

And no, it's not the same gas as here. UK requirements are not the same as US, either federal or local.

 

Yes its the same base fuel it comes in through the south and only bp ultimate can use it. Also I did some research from the epa website. Premium is ultra low sulfur so the sensors are more accurate. Sulfur contaminates the o2 sensors and the readings are not as accurate and the ecu makes slower corrections, Before you throw it back some of the top tier gas stations has ultra low sulfur regular too, but its not every where yet and ethanol free premium is coming back as 91 octane about as hard to find as 100 octane racing fuel.

I never said that the Fit cant use regular. There are benefits from premium.