87 octane vs 89 octane

[pgfpro]

Lots of great info.^^^^^^ Thanks again guys!!!

After looking at all this I think I will stay with my original plain and stay focus on the easier modifications.

[Frank Lee]

Originally Posted by 2000mc

nope, didnt, looked like re hashed version of

http://www.ethanol.org/pdf/contentmg...yStudy_001.pdf

Well... it usually helps some to look at something before you comment on it??? Not only did you blow my link off, you evidently failed to take the time to comprehend the material in YOUR links! (BTW- good finds! )

The studies mirror my experience with the stuff.

It is very safe to say that:

1) claims of fe reduction 1:1 with BTU content are false

2) one should not automatically assume that the presence of ethanol will lower fe

3) non flex-fuel vehicles can function quite well on far higher ethanol blends than E10.

Now what is all that about the Chevy? I didn't see any "excitement" about it.

[2000mc]

#1 and #2 are very similar

#1 if you take out the flex fuel chevy from the report( i'll explain why i have a problem with that vehicles results) the general trend tends to follow the mpg:btu expected mileage, the non flex fuel chevy barely deviates from it

#2 true, but looking at the other vehicles the toyota and ford, they achieved thier best mileage with e30, why that mixture? why not e10, e20 and e40? what is the scientific cause? running lean? if it does hold up, is each vehicle different?

#3 absolutely yes, but i thought the reason for e10 and not more was because of the corrosive nature of the fuel, and that in time various components of your fuel system would fail one after another.

i thought the 15% improvement was suppose to be the excitement.

the flex fuel chevy had the most significant result of +15%. the next most significant result was only +1%. i took issue with the chevy result because the manner that the flex fuel chevy is tested, because it would not be able to correctly learn the fuel content. causing how the chevy ran to be a crap shoot, too rich, too lean, incorrect timing, drivability issues.

i figure if you got a considerable mileage increase from running lean, it would probably show up in emissions...

last line of page 7 from http://www.ethanol.org/pdf/contentmg...inal_12507.pdf

The flex-fuel Chevrolet Impala exceeded the NMOG standard for the FTP-75 on E20 and Tier 2 gasoline.

regflag, what? failed emmisions on straight gas? combine that with the fact that the nonflex fuel chevy had better mileage on straight gas, and i would guess that the flexfuel chevy ran rich on the straight gas and lean on e20. with the straight gas as the baseline figure for comparision, that then gives a bump to all the other ethanol mixtures on the flexfuel chevy.

[Firestone66]

I have experimented with regular 87 and mid-grade 89. They say the best economical speed is around 88 km/h. I assume that is with regular. I have this theory that higher octane raises your best economical speed since it provides more horse power. The reason I say this is because I noticed that going at 100 km/h on mid-grade 89, the rate of liters of fuel burned was the same as going 88 km/h on regular. Liter for liter, I covered more distance on 89 octane. I assume that for those who did not see much gains is because they travelled the same speed for both 87 and 89. My next experiment, I will be using 91 octane, and I will again increase my speed to see if this trend of increasing the best economical speed continues.

[razor02097]

Unless your vehicle pulls timing when you use lower octane fuel you will not benefit from using a higher octane. Period. If the engine runs with full advance on 87 octane, using higher octane fuel will make zero difference.

[rmay635703]

Originally Posted by razor02097

Unless your vehicle pulls timing when you use lower octane fuel you will not benefit from using a higher octane. Period. If the engine runs with full advance on 87 octane, using higher octane fuel will make zero difference.

Most vehicles now days are 10:1 + compression, my vehicle will run full advance on 87 octane but bucks at low RPM and then pulls timing until my rpms increase.

Most new vehicles benefit from higher octane due to the way they can alter timing (OBDII anyone) but the benefit may not be significantly better FE, for me it was about 2mpg going from 87 e10 to 89e10, but on 48-52mpg that is only about 4% or so. It was about the same differance as going from 87e10 to 87e0
Cheers
Ryan

[razor02097]

Car manufacturers tell you what octane they recommend. That is what one should go with. Going higher will just cause you to pay 10-15c per grade per gallon extra. Might not sound like much but if you fill 15 gallons with high octane and pay 20c extra per gallon you pay an extra $3 for absolutely nothing.... instead take the $3 and give it to the homeless man at the end of the fuel station driveway... at least he could put that toward buying himself some booze.

[gone-ot]

Originally Posted by razor02097

Car manufacturers tell you what octane they recommend. That is what one should go with. Going higher will just cause you to pay 10-15c per grade per gallon extra. Might not sound like much but if you fill 15 gallons with high octane and pay 20c extra per gallon you pay an extra $3 for absolutely nothing.... instead take the $3 and give it to the homeless man at the end of the fuel station driveway... at least he could put that toward buying himself some booze.

..sorta like: put the ethanol in the homeless man and let him burn it up (wink,wink)?

[Firestone66]

Originally Posted by rmay635703

Most vehicles now days are 10:1 + compression, my vehicle will run full advance on 87 octane but bucks at low RPM and then pulls timing until my rpms increase.

Most new vehicles benefit from higher octane due to the way they can alter timing (OBDII anyone) but the benefit may not be significantly better FE, for me it was about 2mpg going from 87 e10 to 89e10, but on 48-52mpg that is only about 4% or so. It was about the same differance as going from 87e10 to 87e0
Cheers
Ryan

Maybe I should have stated what vehicle I used. Lol! I used my 2012 F150 for my analysis. My manual also states that it runs at a minimum of 87 octane, which is why I went higher. The bare bone results I received on my 500km rides were this. Regular 87, 74 liters equally $74 at a controlled speed of 95km/h... Midgrade 89, 59 liters equally $62 at a controlled speed of 105km/h. That being said I saved twelve loonies and got to where I wanted to get, sooner... Spend more to save more...

[redpoint5]

Originally Posted by razor02097

Unless your vehicle pulls timing when you use lower octane fuel you will not benefit from using a higher octane. Period. If the engine runs with full advance on 87 octane, using higher octane fuel will make zero difference.

I have an UG and have it setup to show the timing advance. How do I know if it's at full advance?

Originally Posted by Firestone66

The bare bone results I received on my 500km rides were this. Regular 87, 74 liters equally $74 at a controlled speed of 95km/h... Midgrade 89, 59 liters equally $62 at a controlled speed of 105km/h. That being said I saved twelve loonies and got to where I wanted to get, sooner... Spend more to save more...

There is zero chance that going faster, regardless of octane, results in better fuel economy unless your truck shifts to a lower gear between 95kph and 105kph.