Is it still progress?

[gone-ot]

...back to my 'original' point, which is:

1) EPA tests with 100% gasoline, not E10 <--- stated by others.

...and...

2) EPA tests with 91 octane fuel, not 87 octane which MOST engines are specified to use by their manufacturers.


...and, because most current engines can "adjust" operating conditions (ala' knock sensor) to achieve "optimum" results with varying fuel charactoristics (and thus performance)...the EPA tests are using higher-milage 'capability' 91 octane, not the lower 'capability' 87 octane that most people follow.

[Allch Chcar]

Originally Posted by Old Tele man

...from slide 11 of this presentation:

http://www.arb.ca.gov/msprog/levprog...1/alliance.pdf

...it shows, in the right column, the current Federal (EPA) "test fuel" requirements. Note that AKI is always slightly less than the RON number, hence AKI = 91 octane, from RON = 93 octane.

That's a proposal for one standardized test fuel between the CARB and EPA. They are suggesting only testing with Premium grades and use 10% Ethanol.

I don't see how that means they only test with premium.

[gone-ot]

...directly from the title of chart #11:
Current ARB and EPA Certification Fuels

[redpoint5]

Originally Posted by Allch Chcar

redpoint5, Ethanol is infact a more efficient fuel than Gasoline, it is simply not as energy dense. Strangely, Octane for blends from E50-E85 is about the same, 95 1/2 octane AKI, still better than pump gas at 93 but not what you'd expect. Plenty of the hotrodders, tuners, and engine builders swear by it. I've heard E85 is just shy of C16 leaded fuel but either way it is vastly underutilized in a FFV.

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.

[Allch Chcar]

Originally Posted by Old Tele man

...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.

Originally Posted by redpoint5

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.

[jamesqf]

Originally Posted by Old Tele man

...and that "...test grade Gasoline..." is 91-octane (mid-grade), not the typical 87-octane often recommended for most engines! Talk about "gaming" the EPA fuel-economy test system!!!

Strangely enough, I never use anything but regular 87 octane, yet am able to get well over EPA estimated mpg, despite living in a mountainous area which is not favorable to getting high mpg. So who exactly is "gaming" the system?

[gone-ot]

Specific example: operating a turbocharged engine on both higher octane & higher energy content fuel produces better FE because the computer and sensors allow the engine parameters to be "optimized" upward to exploit ALL the benefits of the higher energy (mpg) and octane (advanced idnition timing)...that's "gaming" the system.

Also, notice that ALL tests are done with NO electrical loads, save those during A/C tests only...but, YOU and I do drive at night, don't we?