best mileage gases

[benhuey]

In your experience what gas are best for mileage.
I prefer to use shell in my area, but there are many brands of gas that are not here in my not so metro neck of the woods.
So my question is this: in your experience what is the best gas for mileage??

[SVOboy]

I've never seen any difference I can attribute to brand of gas. Have you seen the thread where nortonpro tested this stuff out?

[benhuey]

never have seen the thread... there are some brands of gas that i will not buy because of poor mileage.
Conoco, speedway, marathon, clark. I don't know if some gases are cleaner, have additives, less alcohol or what, but some do outperform others when it comes to mileage.

[Sludgy]

Some fuels contain more energy that others. Diesel contains about 140,000 btu/gallon. Gasoline is about 147,000 btu per gallon. Propane contains about 90,000 btu/gallon.

Even in gasoline alone, there are differences. Oxygenates contain less energy. MTBE and ethanol and methanol all contain less energy per gallon than straght gas.

Other than this, I don't think the brand of gas makes much difference.

[krousdb]

Originally Posted by Sludgy

Some fuels contain more energy that others. Diesel contains about 140,000 btu/gallon. Gasoline is about 147,000 btu per gallon. Propane contains about 90,000 btu/gallon.

Even in gasoline alone, there are differences. Oxygenates contain less energy. MTBE and ethanol and methanol all contain less energy per gallon than straght gas.

Other than this, I don't think the brand of gas makes much difference.

Hmmm. I always thought that diesel contains more energy per gallon than gasoline. IIRC, gasoline only contains 114,500 btu/gallon and Ethanol contains only 80,000 btu/gallon.

[Sludgy]

OOPS, you're right. Diesel has more energy than gas. <slaps forehead>

[n0rt0npr0]

Not only does my testing show brands make some mileage difference, but even in my car I've seen up to 8% differences between brands.

Link to my testing here.