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Old 03-01-2012, 12:00 AM   #35 (permalink)
Allch Chcar
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Location: North Coast, California
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Cordelia - '15 Mazda Mazda3 i Sport
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Quote:
Originally Posted by Old Tele man View Post
...directly from the title of chart #11:
Current ARB and EPA Certification Fuels
If you'll note, left is the California ARB which uses 91 octane. Right is the Federal certification which uses regular and premium grades.

Slide 10 you can see they are proposing the use of 91 octane for both.

Quote:
Originally Posted by redpoint5 View Post
Good info; it helps to show how the math works out.

What I meant by less performance is less energy content, as you pointed out. People are primarily concerned with how much a tank of fuel costs and how far it will get them. In this way, petroleum is more efficient, otherwise we would all be driving E100 cars with high compression ratios and turbo chargers.

Maybe one day ethanol will be relevant, but this is not that day.
That's confusing because to me, performance is power, octane, efficiency. MPG is a function of fuel economy.

Which one is more economic depends on the market and how efficient your vehicle is. For example, in the Midwest, Ethanol rack prices have dropped to <$2.50 a gallon while Gasoline is well above $3. Here I can buy E70 for $3.09 while Regular Gasoline is $3.59. If Ethanol drops 10 cents or Gasoline rises 10 cents then E70 make economic sense since I will only lose 15%-20% tops. Spring through fall has more Ethanol than winter so prices can actually drop leading up into summer.

But in places like Minnesota, Iowa, the Dakotas, etc they can get E70 for <$3 and Gasoline is the same.
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