Gas brands: does it matter?

[DeusxMac]

The politics of this site aside, if their map is correct, many states have no refineries whatsoever (none in all of New England), so their gasoline would be from out of state.

http://earthjustice.org/features/147refineries

[DinerDave]

josntme wrote:
There is a distribution point in my area that all petro flows thru for all the brands. You can drive by and see trucks bearing the logo's for the brands being loaded from the same tanks. Each brand will put their additive in when the load is dropped at the stations.

This.

The driver pulls up to the terminal, inserts a card that ID's the retailer he is delivering for, and gets the same raw gas as anyone else, PLUS the brand specific detergent additive blend, thus making the fuel match what the retailer advertises.

Think of it as a soft serve ice cream dispenser. All vanilla base, plus your flavor shot to to make the ice cream, pina colada, strawberry, etc.
If you notice any performance issues, then the particular detergent blend is not right for your engine.

Dave

[Markintosh]

Thats what the EPA says about ethanol. In a perfect world, only 3.5% drop in MPG due to less energy. But ethanol absorbs water. Gasoline containing ethanol absorbs much more water from the atmosphere than standard gasoline, so if you're buying from a station that has stored that gas-ethanol for a while, odds are pretty good that it as absorbed a lot of water. That water absorption is not regulated. Real world testing for 10% ethanol in gas results in more of a 6-10% drop in MPG.

davester wrote:
[quote=Markintosh]
If your cheaper gas is because it contains ethanol, then it may not be so cheap. We find that putting the 10% ethanol blends (found in most cheap gas) into our Matrix gives us about a 10% reduction in MPG (from 31 to 28). So that 30 cents saved per gallon becomes somewhat of a wash when we're filling the car 40 miles sooner.

The Chevrons and a few local independents rely on a local wholesaler that seems to have the best gas around for MPG, ethanol free.

How sure are you that your gasoline is ethanol-free? Ethanol labeling is not required in California and very few US gasolines are ethanol-free these days. Also, a number of states (mostly corn belt states) require ethanol in gas. Most premium gasoline has extra ethanol in it to help raise the octane level. Also, it's impossible to reduce your gas mileage by 10% by using 10% ethanol blend since ethanol burns at 75% of the efficiency of gasoline. The worst reduction in gas mileage you could get would be 3.5%. You'd need to be running 10% water to get a drop that big.

[davester]

Markintosh wrote: Real world testing for 10% ethanol in gas results in more of a 6-10% drop in MPG.

Please provide a link to this real world testing. I looked and found nothing but results in the 3% range. To get a 6% drop in mileage the ethanol would have to have absorbed 50% water by volume, and as I noted earlier, to get to 10%, all the ethanol in E10 would have to have been replaced by water. That's just not reasonable.

[Racer X]

Markintosh wrote:
If your cheaper gas is because it contains ethanol, then it may not be so cheap. We find that putting the 10% ethanol blends (found in most cheap gas) into our Matrix gives us about a 10% reduction in MPG (from 31 to 28). So that 30 cents saved per gallon becomes somewhat of a wash when we're filling the car 40 miles sooner.

The Chevrons and a few local independents rely on a local wholesaler that seems to have the best gas around for MPG, ethanol free.

10% mix should only be a 3% reduction in fuel effeciency. Lower energy content. Your Matrix must be an anomaly. E85 is horrific for fuel economy.

[Filliam H. Muffman]

3% only accounts for the energy loss due to 10% ethanol. I could see that with the octane buffer that ethanol provides, it might allow a refinery to make up with straight run components that have lower energy. The pump octane is R+M/2, so a high Research number and a lower Motor number would get lower mileage in a high performance engine that has knock sensors. I don't have enough experience to know what 10% ethanol does to the Research and Motor numbers.

[Mr645]

You can find ethanol free gas anywhere boats are popular. Since Ethanol both damages fiberglass tanks, and absorbs water, it's not used for marine applications.

[NewtonMP2100]

....what you eat....can also determine the smell of.....your gas......