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Discussion Starter #1
I came across this website today.

As most of us heard / understand - Ethanol degrades engine performance.
Since most fuel now are at least 10% ethanol - do you think we will notice an increase in engine performance if we switch back to pure gasoline?

I called the station closest to me that sells Ethanol Free gasoline and the price for 92 unleaded ethanol free is the same as 92 unleaded with ethanol ($3.85 / gallon.)

Input from anyone?

I plan on getting some this Sunday and try it. Will report back.

Ethanol-free gas stations in the U.S. and Canada
 

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I came across this website today.

As most of us heard / understand - Ethanol degrades engine performance.
Since most fuel now are at least 10% ethanol - do you think we will notice an increase in engine performance if we switch back to pure gasoline?

I called the station closest to me that sells Ethanol Free gasoline and the price for 92 unleaded ethanol free is the same as 92 unleaded with ethanol ($3.85 / gallon.)

Input from anyone?

I plan on getting some this Sunday and try it. Will report back.

Ethanol-free gas stations in the U.S. and Canada
Dan,

As usual, you are a fountain of information! There is one about a mile from my home in Prairieville. I will fill up tonight and let everyone know what the findings of the Butt-O-Meter tell me.

On a similar note, have you tried blending higher octane/race fuel on a consistent basis? I have been thinking of doing so. Any thoughts?

Milton
 
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Sweet.....there is one about 10 miles from me.

My only concern is, at least the ones listed for the state I live in are not "Top Tier" brands.
 

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Discussion Starter #4 (Edited)
Thanks Milton! And great question about high octane gas.
I actually have a post here on that.

Summary:
During summer time, roads are dry, we get the best tire adhesion, we can really drive our cars spiritedly without slipping and sliding - I go to a local Shell gas station about 4 miles from my house that sells 101 octane.

I get about 5- 6 gallons of 100 octane on an almost empty tank, then fill up the rest with 92 super unleaded.

I tell you - our M engines just loves it! Amazing engine performance improvement.

I found my post, here it is:

http://www.m5board.com/vbulletin/e6...ard-com/164851-high-octane-gas-trick-gas.html



Dan,

As usual, you are a fountain of information! There is one about a mile from my home in Prairieville. I will fill up tonight and let everyone know what the findings of the Butt-O-Meter tell me.

On a similar note, have you tried blending higher octane/race fuel on a consistent basis? I have been thinking of doing so. Any thoughts?

Milton
 

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Dan,

On a similar note, have you tried blending higher octane/race fuel on a consistent basis? I have been thinking of doing so. Any thoughts?

Milton
Careful on this one ...
you will get better performance and less pre-detonation with higher octane race fuels but you must be aware of a few things.
First, many fuels above 100 octane are leaded ... so make sure you aren't putting leaded fuel in an unleaded engine
Second, higher octane fuels can run higher engine temperatures.
Also, octane boosters (especially) and high octane fuels can wreak havoc on seals & gaskets ... so be wary


All that aside, you can see some impressive horsepower gains from race fuels ... just use them sparingly and only put in enough fuel for a few laps at a local track first. You don't need the extra fuel weight, race fuel is expensive, and this way you aren't stuck with a full tank of gas that you don't feel the gains are worth the costs. :D
 

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Discussion Starter #6
I hear you - I dont put any non top tier gasoline brands either on my beast.

Luckily, the one closest to me with ethanol free is Union 76 brand so I will try it.

FYI, on my beast, 95% Chevron fuel. The other 5% is either Shell or Union 76 when Im really low on gas and cant find any Chevron.

Sweet.....there is one about 10 miles from me.

My only concern is, at least the ones listed for the state I live in are not "Top Tier" brands.
 

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Thanks Milton! And great question about high octane gas.
I actually have a post here on that.

Summary:
During summer time, roads are dry, we get the best tire adhesion, we can really drive our cars spiritedly without slipping and sliding - I go to a local Shell gas station about 4 miles from my house that sells 101 octane.

I get about 5- 6 gallons of 100 octane on an almost empty tank, then fill up the rest with 92 super unleaded.

I tell you - our M engines just loves it! Amazing engine performance improvement.

I found my post, here it is:

http://www.m5board.com/vbulletin/e6...ard-com/164851-high-octane-gas-trick-gas.html
Dan,

Thanks! A friend of mine who works at ExxonMobil is going to email me a blending chart and I will place it in this thread to accompany your information.

Milton
 
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I get about 5- 6 gallons of 100 octane on an almost empty tank, then fill up the rest with 92 super unleaded.

I tell you - our M engines just loves it! Amazing engine performance improvement.

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+1 Dan, it was an amazing ride back last summer after getting Tubi installed, and you turned Ajax on to the location for the trick gas, out back behind the Shell station from the secret door. And take it from Ajax, the trick gas has a nice sweet smell that is a delight to the nostrils while refueling.
 
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That is a end user generated report so I would be cautious about CENEX as the last time I checked it had ethanol, AND it is not top tier fuel. It doesn't make sense to me that one Union 76 wouldn't have ethanol when all the rest do - it may just be a lack of labeling at that station.

However it is completely possible that the Conocos in eastern Washington would be ethanol free as they don't have the air requirements we have on this side of the mountains and that fuel comes from the east (I think the Conoco Phillips Refinery in Billings)

I think you were talking about Thrasher's Corner Shell in Bothell which has the 101 unleaded. I go there to mix half and half with premium in my M3 to avoid ping due to its high compression. On trips I have to take a race tank with me. $8.58 a gallon though. The only other station I know that has race gas is the 76 Station on Auburn Way north of 15th.

I have found octane boosters do not work. 101 unleaded does work. :grinyes:
 

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Discussion Starter #10
No CENEX gas for me. Never have, never will. Only top tier gas.

I live in Everett and I plan on stopping by Union 76 in downtown Everett to check out their ethanol free 92 super unleaded.

The thing is - if its only a sign gimmick - how would I or anyone verify if their gas is truly ethanol free?

And yes Mark, Thrashers Corner Shell is the one that has 101 octane unleaded gas.
In fact, last time I filled up my M6 there were 2 other BMW owners waiting to fill up too.

Boy, I tell you, our BMW's just love higher octane gas.
I determined that 95 total octane is best. Anything more than that produced no significant improvement in engine performance.

That is a end user generated report so I would be cautious about CENEX as the last time I checked it had ethanol, AND it is not top tier fuel. It doesn't make sense to me that one Union 76 wouldn't have ethanol when all the rest do - it may just be a lack of labeling at that station.

However it is completely possible that the Conocos in eastern Washington would be ethanol free as they don't have the air requirements we have on this side of the mountains and that fuel comes from the east (I think the Conoco Phillips Refinery in Billings)

I think you were talking about Thrasher's Corner Shell in Bothell which has the 101 unleaded. I go there to mix half and half with premium in my M3 to avoid ping due to its high compression. On trips I have to take a race tank with me. $8.58 a gallon though. The only other station I know that has race gas is the 76 Station on Auburn Way north of 15th.

I have found octane boosters do not work. 101 unleaded does work. :grinyes:
 

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Dan,

Thanks! A friend of mine who works at ExxonMobil is going to email me a blending chart and I will place it in this thread to accompany your information.

Milton
Guys,

Here is the blending chart for 93 octane...
 

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Guys,

Here is the blending chart for 93 octane...
Here is the blending formula for mixing any two fuels with different octanes:

Oa = Octane of Gas-a Ga = Gallons of Gas-a
Ob = Octane of Gas-b Gb = Gallons of Gas-b

So the final octane will be the weighted average, or:

Oa*Ga + Ob*Gb
------------------
Ga + Gb

Checking this against the Blend Chart, Oa = 93, Ob = 100, Ga = 4 (on the left of the chart), Gb = 9 (on the top), Chart says 97.8, formula says 97.846.

Another check: Oa = 93, Ob = 100, Ga = 7 (on the left), Gb = 8 (on the right), Chart says 96.7, formula 96.733.

Turning this around, if you know the octanes of the gasolines that you want to mix, and you know the resulting octane you want to end up with...

If Ox is the octane you want to get to, then... given gas with octane Oa which is less than Ox and gas with octane Ob which is greater than Ox, you can take (Ob-Ox) : (Ox-Oa) to find the "mix ratio" to get to Ox.

Thus, if you only have 92 octane gas and 101 octane race fuel and you want to get 95 octane results, the "mix ratio" is (101-95) : (95-92) which is 6:3 or equivalently 2:1 mix, so if you mix 2 gallons of 92 to every 1 gallon of 101 you get 95 octane, since (2*92+1*101)/(2+1) = 95.

Back to the chart, starting with 93 and 100 and a desired result of 95, you mix (100-95) : (95-93) which is a 5:2 or equivalently 10:4 ratio to get 95 octane (see 10 gallons of 93 octane with 4 gallons of 100 octane on the chart - it checks out).

-crds
 

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Here is the blending formula for mixing any two fuels with different octanes:

Oa = Octane of Gas-a Ga = Gallons of Gas-a
Ob = Octane of Gas-b Gb = Gallons of Gas-b

So the final octane will be the weighted average, or:

Oa*Ga + Ob*Gb
------------------
Ga + Gb

Checking this against the Blend Chart, Oa = 93, Ob = 100, Ga = 4 (on the left of the chart), Gb = 9 (on the top), Chart says 97.8, formula says 97.846.

Another check: Oa = 93, Ob = 100, Ga = 7 (on the left), Gb = 8 (on the right), Chart says 97.8, formula says 96.7, formula 96.733.

Turning this around, if you know the octanes of the gasses you want to mix, and you know the resulting octane you want to achieve...

If Ox is the octane you want to get to, then... given gas with octane Oa which is less than Ox and gas with octane Ob which is greater than Ox, you can take (Ob-Ox)/(Ox-Oa) to find the "mix ratio" to get to Ox.

Thus, if you only have 92 octane gas and 101 octane race fuel and you want to get 95 octane results, the "mix ratio" is (101-95) : (95-92) which is 6:3 or 2:1 mix, so if you mix 2 gallons of 92 to every 1 gallon of 101 since (2*92+1*101)/(2+1) = 95 octane.

Back to the chart, starting with 93 and 100 and a desired result of 95, you mix (100-95) : (95-93) which is either 5:2 or 10:4 to get 95 octane (see 10 gallons of 93 octane with 4 gallons of 100 octane on the chart - it checks out).

-crds
Thanks for the verification and additional information. The formula provides the flexibility for everyone's use. For the most part, our premium fuel is 92 or 93 octane. I've noticed in other areas that 91 octane fuel is also considered premium. :cheers:
 
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Discussion Starter #16
It is interesting indeed re: octane rating.

Here in Washington State, octane available are 87, 89 and 92.

I travel regularly to California and the highest I can find for super unleaded is 91.

I wonder why that is.

Anyway, ours here is 92 and I have determined that 5 gallons of 100 octane is what works best to get 95 total octane.

I tell you, our beast just loves 95 octane. I cant wait till weather improves so I can get trick gas again!
 

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I hope to try mixing this coming weekend! I've done research and Sunoco makes an unleaded race fuel that is available at their Master Dealers. I will call the regional distributor and gather additional information which I will add to this post.

I can only surmise that different air quality standards help determine the octane levels locally, but I'm only guessing! Maybe one of our petrochemical board members can help? :dunno:
 
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I hope to try mixing this coming weekend! I've done research and Sunoco makes an unleaded race fuel that is available at their Master Dealers. I will call the regional distributor and gather additional information which I will add to this post.

I can only surmise that different air quality standards help determine the octane levels locally, but I'm only guessing! Maybe one of our petrochemical board members can help? :dunno:
It is worth noting that the "mix" isn't that exact. We have 18.5 gallon (US) tanks (low fuel light comes on around 16 gal). Ideal mix of 93 and 100 octane to get 95 octane is 5:2 or 10:4 which are either 7 gallons or 14 gallons. Without going nuts on measuring, if we need to add 18 gallons to the tank (shame on you for letting it get this low LOL), we can choose 13:5 (13 gal of 93 plus 5 gal of 100) and end up with 94.94 octane mix. If you aren't as "empty" here are some choices:

Need to add 17 gallons? 13:4 is 94.64, 12:5 is 95.05, 11:6 is 95.47

Need to add 16 gallons? 12:4 is 94.75, 11:5 is 95.19, 10:6 is 95.62

Need to add 15 gallons? 11:4 is 94.87, 10:5 is 95.33, 9:6 is 95.8

As you can see, it isn't that "critical" of a selection. No need to measure below 1 gallon to get close.

If you have 93 already in your tank, throw an extra gallon of 100 in and that will bias it up a little...For example, if you had 1.5 gal of 93 so you need to add 17 gallons, add the mix 11:6 instead of 12:5, meaning you'll be adding 17 gallons of 95.5 octane to 1.5 gal of 93 and you'll end up with 95.3 octane.

Another way to do this is this: presuming you wait until you need at least 12 gallons to fill your tank, you start with 5 gallons of 100 octane and then top it off with at least 7 gallons of 93 octane: you'll never go below 95 or above 96 octane no matter how many times you fill the tank. If 5 gallons of 100 octane is too much for your wallet every week (or you don't want to push 96 octane or some reason) and you select to use 4 gallons of 100 octane as your "base" for the mix, the range will be 94.5 to 95.3 octane (still really pretty close for most daily drivers).

To be nice to the guys across the drink, translate the last paragraph to "you need at least 45 liters" start with 19 liters of 100 octane, then top it off, that will get you between 95 and 96 octane. Or start with 15 liters and top it off to get into the 94.5 to 95.3 octane range."

I hope I didn't make you all numb ouich

-crds
 

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I travel regularly to California and the highest I can find for super unleaded is 91.

I wonder why that is.
I do know that at higher elevations you can use a lower octane. I lived in Denver 4 years and 91 is the highest available. At higher elevation there is less air pressure, so less air gets into your motor. That makes your compression lower, which means that your motor is less likely to "ping" (Pre-ignite or knock) on lower octane fuel.
 
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