I have filled up the past two times at 7-11. It says that up to 10% of the fuel could be ethanol. Is that bad? Mileage has been similar on tanks so just wondering if it could damage the c5. thanks for any input!

 

7-eleven gas is fine, it comes up the same Colonial pipeline as every other brand of gas in your region

 

The ethanol issue is a different story. Ethanol will ultimately reduce your fuel economy. It dropped my fuel economy (in recent tests) 2.5 mpg in my truck. The final test will be a mid winter run when the air temp cools off. Can't accurately tell in the vette, since I'm running rich.

 

1% ethanol gas won't hurt anything. You may end up with less mpg, but that's about it.

 

But it's up to 10%!

 

Up to 10% is fine. However, expect your fuel mileage to drop by about 8% from pure gasoline. Try not to use ethanol-blended gasoline in a vehicle that's stored for more than about 4 months. The fuel 'sours' more quickly than 100% gasoline.

 

10% ethanol is pretty much everywhere(At least in the mid-west and every where I've been) and causes no problems(Other than the mentioned loss of MPG)!! E85 would on the other hand cause All kinds of problems!!!

 

Here in Nevada we been using 10% for years and never has any issues, Now as far as 7-11 gas thats another story, Had issues with gas fron them a few years back, Will never burn it in my Vette, Only Chevron for me.

 

i work in the petrochemical industry and feel i need to shed some light on gasoline. after all the help i have gotten on the board it's the least i can do.

without getting too technical...
gasoline is gasoline.
a tanker truck pull up to a loading terminal outside a chemical plant and loads his tanks. say the plant has a big sign out front that says Shell.
he swipes a card and receives a load of say 87 octane gasoline. if he is taking that to a Chevron station the gasoline will be mixed with techron and other additives while it's being pumped into the tank. Gasoline that is going to 7-11 will be to minimum 7-11 spec. it could be un-blended 87 octane, 89 or whatever.

now the tricky part. the Chevron station will have certified tanks and corporate testing of gasoline so you get an "assured product". with 7-11 i would not put it past the owner of an independent station to add a little tap water to the gasoline. since gasoline can absorb a certain amount of moisture from the air and still be combustible the store owner can cheat the customer out of the highest quality gas for a little bit of profit.

now knowing this what gas do you think i run in my Vette?

 

Greate post.....thanks

 

My cousin once told me that there's a local Shell station whose owner add water into their gas. As a result, one of his friend's car's engine had to be replaced. Now obvioulsy I have no personal experience, so I'm not accusing anyone. However, I avoid that store already because of their customer service. They are the least friendly Shell in town, and on top of that, the owner likes to "stare" at you.

I have a shell gas rebate card so I get 5% back. It really saves a lot in the long run.

 

Thanks for all the info... Ill monitor my mpgs and go from there. But paying 2.61 for premium is pretty nice...as long as it really is premium

 

It cut my mileage.

 

The only gas I get from 7-11 comes from the lousy food they sell.

 

7-11 fuel is sub $2 right now, but I still buy amoco ultimate from my local BP. the extra $3 it takes to fill the tank is well worth it.

 

I work in the petroleum transportation industry, and at least in Michigan and surrounding States, I find there are very few stations that don't have 10% ethanol now. The law used to require that it be posted at the pump, but it no longer is necessary. Ethanol raises the octane and allows lower octane gas to be bumped up reducing the suppliers costs. Lately though, the price of ethanol and the handling of it has wiped out that savings. Ethanol cannot be sent through the pipelines to the terminals and is trucked in. That being said, there is an advantage to ethanol in that any water introduced into the tank will cause a phase seperation making the product unuseable. I am not a fan of ethanol. My 81 hated it and my last holdout station in the area finally went to ethanol. But it is here and unavoidable. E85 for flex fuel vehicles is becoming more prominent in this area. It will give you 10-15% poorer mileage, but it is priced at $1.72 in town today which offsets that if you can burn it. You also have to remember that our racing Vettes are now running pure ethanol and E85. What you really need to watch for is the unscrupulous dealers who water down their premium with 87 octane. We constantly have dealers who order too much 87 and then ask the drivers to just put it in the premium tanks. We will not do that but there are those that will. The dealer faces big fines if caught, but many are willing to take that chance. It is best to buy from Major Oil, company owned stations.

 

I also work for an oil company and I agree with you up to a point. One possible benefit of 10% ethanol is that ethanol does not play well with water. If a station's underground storage tank has more than 1% water content, that will result in what is called phase separation. When phase separation occurs, the water binds with the ethanol and falls to the bottom of the tank and the gas is no longer to specs. At this point legally the station would have to pump all the fuel out of the tank at his/her expense and take a loss for the cost of the fuel that was pumped out. When the stations in my area switch the 10% ethanol from MTBE, all the tanks had to be cleaned out prior to the first delivery of gas mixed with ethonal to insure there would be no water contamination. MTBE, which ethonal replaced, on the other hand does have a high tolerance for water and you would often find large amounts of water at the bottom of the tank from condensation. If you where unlucky and received fuel from the bottom of the tank you ran the risk of H2O contamination; with ethonal this is really not a problem anymore.

 

Damn, so why am I paying more for Chevron and Shell?

-Alex

 

I quit buying 7-11 fuel because it's all CITCO out here

 

7-eleven uses gas as a loss leader. They are not out to make money on gas so much as to lure on to the parking lot in hopes you will buy a Big Gulp or some other in store item where they make a huge profit margin. Same holds true for Wawa and Sheetz. Also, you are paying for the brand name