Mileage with Top Tier fuel/ethanol?

[Flashlightboy]

Top Tier fuels can contain up to 10% ethanol however isn't ethanol a poor energy source when compared to a comparable amount of gasoline?

If so, then I'm likely seeing a decrease in my mileage but is there a rough forumula to help figure this out?

We've got cleaner engines/fuel systems but less mileage. Is this a cost/benefit win? I recall similar discussions when California started used MBTE.

 

[Blue99]

The Chevron website pegs the amount of energy reduction at 3.5% for E10 vs conventional gas.

Here is the Link To Chevron Ethanol Info.

Actually, what happens, is that with the addtion of ethanol, with an octane rating of 113, the refineries are able to remove some other higher BTU & more volatile components from the formula and still meet the same minimum octane requirements.

I think a 2-3% reduction in actual gas mileage vs. conventional gas is a good figure.

We've used an EPA required 10% ethanol blend in the Chicago-Milwaukee area since 2001.

 

[jbas]

A "MotorWatch" spokesperson reportedly said recently that brand-name gasoline can contain up to 20% alcohol, resulting in a 10% to 15% reduction in gas mileage. That seems like an unrealistically high level, especially compared to the Chevron numbers.

 

[Palut]

quote:

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Originally posted by jbas:
A "MotorWatch" spokesperson reportedly said recently that brand-name gasoline can contain up to 20% alcohol, resulting in a 10% to 15% reduction in gas mileage. That seems like an unrealistically high level, especially compared to the Chevron numbers.

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I see at least a 10% mileage hit every time I use oxygenated fuel in my Accord.

 

[TwoLostMinds]

I wonder how much we are really reducing emissions by using oygenated gas....
I mean, if oygenated gas reduces emissions by say 10 - 20% but we are burning 10 - 20% more fuel because of the MPG hit wouldnt it just even out and do nothing but put money into "big oil's" pockets?
Does anyone have access to the actual emissions numbers when using oxygenated vs regular gas?
i>

 

[Mike_dup1]

per the 2005 fuel econmy guide (EPA)

typical example

2005 Ford Explorer 4x2 E85 (85% ethanol/15% gas)
11 city / 15 hwy

Same with 100% gas
15 city / 20 hwy

 

[Rickey]

"Top Tier fuels can contain up to 10% ethanol however isn't ethanol a poor energy source when compared to a comparable amount of gasoline?" Someone correct me here if I am wrong: Aren't all on road gasolines the same with respect to ethenol content, and the ethenol content is determined by region not by top tier status. Wouldn't want any one to interpret this thread to mean that all top tier has ethonol. There are still lots of areas that don't require oxigenated gasoline. Yes alcohols generally have about 50 percent of the caloric content of gasoline. And since they carry some of their own oxygen the engine gets a slight chemical supercharging effect. In other words IF everything is adjusted to optimum more alcohol content equals more power. This requires more fuel volume and results in less fuel mileage of course. Rickey.

 

[andyd]

for whatever reasons, I see a 10% reduction in MPG in the winter time

 

[Palut]

quote:

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Originally posted by TwoLostMinds:
I mean, if oygenated gas reduces emissions by say 10 - 20% but we are burning 10 - 20% more fuel because of the MPG hit wouldnt it just even out and do nothing but put money into "big oil's" pockets?
i>

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I bet the government will want ethanol in gas just so that we get worse mileage, no matter what it does for pollution. If we all get worse mileage, we buy more gas, which means more gas taxes!

 

[MNgopher]

IIRC, there is no requirement that Top Tier fuels contain ethanol. That is still set by federal/local gasoline requirements.

In general, 10% ethanol/gasoline blends will result in a 2-5% reduction in fuel mileage, per fleet testing, to a comparable non-ethanol containing gasoline.

Highly unlikely that any brand name retailers offer anything any higher than 10% ethanol blends without labeling it. Likely they would get an earful from consumers. Spot checks in this area gerally shows ethanol content between 9.5 & 10.5 %, depending on supplier and time of the year.

andyd, likely the total 10% reductions are do to many other factors in conjunction with any switch to an oxygenated fuel. No way to pin all the 10% reduction on the fuel. This has been hashed out, over and over again. I see a swing of over 10% in fuel mileage from my best month to worst month, yet we use ethanol year around by state law. The swing correlates very nicely with the corresponding tempartures curing the period, not to the fuels used.

In terms of the government wanting ethanol fuel to increase tax income, the reality is exactly the opposite. Ethanol blended fuels generate less income for the govenrment due to the net decrease in gasoline consumed. This has been an issue in several of the last transportation bills, as the government has tried to figure out how to recoup the taxes lost from the 10% blends.

 

[ARH_0700]

A little off topic but how can one tell what % ethanol is used by a particular station? I use Shell V-Power 93 exclusively and none of the stations around my area seem to have anything posted about ethanol. I know we get oxygenated fuel, though (montgomery county, MD) so how can I find out? Do I need to ask, or do I need to look more carefully?

 

[Blue99]

quote:

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A little off topic but how can one tell what % ethanol is used by a particular station?

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Many states require the ethanol content to be posted at the pump.

Based on this U.S. Gasoline Requirements Map most of Maryland is an RFG area and some areas are conventional gas.

A quick web search turns up numerous current references to MTBE ground water contamination in Maryland, so the oxygenate is most likely MTBE and not ethanol.

 

[TwoLostMinds]

....throwing another .02 cents in
Just pulled up fuel records from our '03 Santa Fe
12.5% drop in fuel economy from mid November to end of Febuary.

quote:

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Does anyone have access to the actual emissions numbers when using oxygenated vs regular gas?

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""quoting myself""

I truely wonder if its worth it.

 

[MNgopher]

The only question is, how much of the drop is fuel related, and how much of it is related to other factors, particulary temperature - longer run times in open loop while warming up, more idling, overcoming the thicker lubricants in all driveline parts (grease, ATF, diff lubes, wheel bearings, etc.), lower air pressure in the tires if not compensated for, etc...

I note an 11% decrease in fuel mileage from worst month average (January) to my year round average. That on 10% ethanol blends year around. Best month to worst is over a 20% difference. Winter fuels are a different blend (more light stuff for easier starting) but the energy content is not that much different in this area (again, all 10% blends, year around).

All in all my point is that you cannot pin all of the decrease on a switch to an oxy fuel - lots of other factors coming into play!

 

[wiswind]

As Blue99 stated, Certain regions require "Oxygenated" gasoline that is government mandated for that particular region. Here in Southeast Wisconsin, and the Chicago area.....ALL stations will be selling the reformulated gasoline....which, in this region has the ethanol....be it from a "Top Tier" station or not.
For me......I would burn FAR more gasoline driving 2 counties away to buy "normal" gasoline....then what I would save in mileage....

Reformulations required by the Fed's will vary from region to region....which may give you different results.

Top Tier....as I understand it.....has to do with the additive package that is added to the base "reformulated" or un-reformulated fuels for a particular branded station.....which results in the detergency required for the "Top Tier" rating.

Some of us add a small amount of a detergent additive on our own. From what I have read, it is benefical for the additive to also provide lubrication to the fuel system, as well as detergency.....when being used on an ongoing basis...in a "maintenance" dosage.