Non-Ethanol gas

[Skuronen]

Just curious if many people have the option to buy non-Ethanol in their area and if so...how often do they fill up with that as opposed to regular 93 octane.

I have been filling up with non-ethanol since taking possession of the car, but I am wondering if it is truly worth the 4.39 a gallon (93 octane) if you run your car often and the gas does not have a chance to sit long.

Any experience or chemical opinions on this? Thanks.

[seank]

I wish we had 93 octane. California 91 is more like a 90 on the tests that I have seen. BTW in California, 91 octane is about $4.39, so I would be happy with that.

[krusty]

Originally Posted by Skuronen

how often do they fill up with that as opposed to regular 93 octane.

Eh? Who fills up with 93? Only use 98.

[3002 tii]

Originally Posted by krusty

Eh? Who fills up with 93? Only use 98.

LOL, 98 RON in Australia is 91.5 AKI USA

[Aries326]

I don't know much about gas. Which would be better to run on your car? 91 octane ethanol free or 93 octane 10% ethanol?

[krusty]

Originally Posted by Dubbedown

LOL, 98 RON in Australia is 91.5 AKI USA

I think the petrol used in Australia mostly comes from the refineries in Singapore these days. According to the Wiki chart, ...


http://en.wikipedia.org/wiki/Octane_rating

... 98 RON would be 93-94 AKI.

[jckent]

I may be imagining it, but i can feel a difference in performance when I fill up with regular gas ( which has up to 10% ethanol here in Manitoba). Normally I stay with the highest grade i can get, but when I fill up in my home town I have to use regular.. ( one horse town)

[mike519]

Originally Posted by jckent

I may be imagining it, but i can feel a difference in performance when I fill up with regular gas ( which has up to 10% ethanol here in Manitoba). Normally I stay with the highest grade i can get, but when I fill up in my home town I have to use regular.. ( one horse town)

A lot of Petro Canada's have Ultra 94...love it!

[WestCDA]

I may be imagining it, but i can feel a difference in performance when I fill up with regular gas ( which has up to 10% ethanol here in Manitoba).

I doubt you are imagining it. Ethanol contains substantially less energy per volume than gasoline - you'll also get reduced mileage. I try to avoid ethanol blends whenever possible.

[aerobod]

Originally Posted by WestCDA

I doubt you are imagining it. Ethanol contains substantially less energy per volume than gasoline - you'll also get reduced mileage. I try to avoid ethanol blends whenever possible.

Ethanol has a stoichometric ratio of 9:1 vs 14.7:1 for gasoline, so with an energy density of 21.2 MJ/l compared with 34.8MJ/l for gasoline, ethanol liberates 2.356 units of energy compared with 2.367 units for gasoline for every unit of air it combusts with. This is less than 0.5% difference in energy liberated (although 63% more ethanol is burned by volume).

Basically with E10 gasoline, energy liberated is within 0.05% of pure gasoline with approximately 4% increase in fuel consumption. Bear in mind that pure ethanol has an octane rating of 109, so it is well suited for blending with gasoline for higher octane levels without the need for additives such as MBTE or lead.

[zBone]

Originally Posted by aerobod

Ethanol has a stoichometric ratio of 9:1 vs 14.7:1 for gasoline, so with an energy density of 21.2 MJ/l compared with 34.8MJ/l for gasoline, ethanol liberates 2.356 units of energy compared with 2.367 units for gasoline for every unit of air it combusts with. This is less than 0.5% difference in energy liberated (although 63% more ethanol is burned by volume).

Basically with E10 gasoline, energy liberated is within 0.05% of pure gasoline with approximately 4% increase in fuel consumption. Bear in mind that pure ethanol has an octane rating of 109, so it is well suited for blending with gasoline for higher octane levels without the need for additives such as MBTE or lead.

[David70]

Originally Posted by aerobod

Ethanol has a stoichometric ratio of 9:1 vs 14.7:1 for gasoline, so with an energy density of 21.2 MJ/l compared with 34.8MJ/l for gasoline, ethanol liberates 2.356 units of energy compared with 2.367 units for gasoline for every unit of air it combusts with. This is less than 0.5% difference in energy liberated (although 63% more ethanol is burned by volume).

Basically with E10 gasoline, energy liberated is within 0.05% of pure gasoline with approximately 4% increase in fuel consumption. Bear in mind that pure ethanol has an octane rating of 109, so it is well suited for blending with gasoline for higher octane levels without the need for additives such as MBTE or lead.

You seem to know what you are talking about. As I don't understand most of what you said, basically in the end, you might see your 21 mpg go to 20 (roughly 4% reduction)?

In other words, what does this mean to what will actually happen?

[MZHammer]

Originally Posted by mike519

A lot of Petro Canada's have Ultra 94...love it!

+1!!!

[Skuronen]

Ha! Looks like I got my chemical opinion!

[WestCDA]

To quote this paper from the EMA (Engine Manufacturer's Association):

The energy content of neat ethanol (E100) is about thirty-five percent (35%) lower than
that of petroleum-based gasoline (on a volume basis). Actual power loss and fuel economy
reduction associated with ethanol blends will vary depending on the percentage of ethanol
blended in the fuel and the engine’s ability to adjust combustion control parameters.

In their conclusions, they do state that blends of 10 percent or lower do not result in 'observable' reductions of power or fuel economy. Based on the observed miles I get from a motorcyle tank of fuel driven under similar conditions, I disagree.

[Doctor Jeff]

Originally Posted by jckent

I may be imagining it, but i can feel a difference in performance when I fill up with regular gas ( which has up to 10% ethanol here in Manitoba). Normally I stay with the highest grade i can get, but when I fill up in my home town I have to use regular.. ( one horse town)

You are not imagining it.

http://www.caranddriver.com/features/regular-or-premium

The BMW M3 they tested lost 6.6% in performance using regular (though no harm to engine). That jibes with what I read in Consumer Reports, where they noted a 5-6% decrease in HP when cars designed to use premium fuel use regular. The "average" driver may not notice anything, but I imagine most Z4 drivers would!

When forced to fill up with regular out of necessity I secretly cry a little...

[Doctor Jeff]

BTW, this being the Cornhusker state, it is hard to find non-ethanol gas anywhere, so I can't worry too much about putting a corncob in my tank.

[aerobod]

Originally Posted by David70

You seem to know what you are talking about. As I don't understand most of what you said, basically in the end, you might see your 21 mpg go to 20 (roughly 4% reduction)?

In other words, what does this mean to what will actually happen?

You are correct in assuming about 1mpg rincrease in the fuel consumption between 100% gasoline and E10.in a Z4M.

[RichardTS]

Originally Posted by David70

You seem to know what you are talking about. As I don't understand most of what you said, basically in the end, you might see your 21 mpg go to 20 (roughly 4% reduction)?

In other words, what does this mean to what will actually happen?

On a pure energy liberated basis with no regard to volume consumed I once calculated that 24 mpg with pure gasoline would translate to 22 mpg with 10% ethanol.

In the last year I have been doing a LOT of highway driving. Notice that the sign on the pump in the U.S. says UP TO 10% ethanol. I can tell you that with absolutely no rhyme or reason my gas mileage varies between 22-24 mpg while averaging 67-70 miles an hour on mixed interstate and 2-lane roads. This is occurring on exactly the same route. My total time for the trip generally varies less than 15 minutes out of 6:30-6:45 hours. I also use the same gas stations.

I suspect the differences are in the % ethanol at any given time. Although completely empirical and non-scientific this seems to validate my simple calculation.

[davesz4mc]

It seems in the US they turn up the ethonal in the winter and lower it in the summer months for polution control, as per the up to 10% ethonol.

[Uncle Russ]

My experience driving the same interstate route & distance with the cruise set at 3000 rpm has consistently given me 26-27 mpg on 100% gasoline and 24-25 using E10.

[TexasZed4MC]

I would be thrilled to have an optional non-ethonol gas! Here in this part of Texas its just not available.