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Old 09-10-2018, 05:40 PM   #173 (permalink)
DGXR
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Quote:
Originally Posted by hat_man View Post
Don't get me wrong, I'm sure the extra lubrication is beneficial (especially to engine longevity) but if adding it to the fuel mix cleans out the injectors, and maybe the spark plugs (and keeps them clean with every application), wouldn't that increase FE a little? I'm not sure how it affects or counters the ethanol in fuel, but we have all read (and I think most agree, but I could be wrong) that non-ethanol "straight gas" gives a bit better FE than ethanol blended fuel. Maybe from the ethanol attracting water and not burning as well?
Non-ethanol "straight gas" (aka E0) has a higher energy content by volume (energy density) than E10. So the same engine will get better fuel economy running E0 than running E10.

Here is the rub: ethanol, by volume, has a higher octane rating than straight gasoline. But somehow ethanol has a lower specific energy than gasoline...? I never understood how this is possible, but this my understanding.

Finally, in E10, ethanol is blended with lower octane fuel to achieve the desired octane. In other words, even though ethanol has higher octane than gasoline, regular grade E10 has the same octane as regular grade straight gas.
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