How doe Ethanol affect gasoline

[chefwong]

Prior this fall, when switching from Mobil to Sunoco, I did notice that the car did not have as much *pep* with the Sunoco gasoline. I didn't realize it at that time, but all Sunoco gas contains 10% ethanol.

With the new law requirement, all gas in NY have 10% ethanol in it. I just got a fillup in the next state over, NJ (Mobil fillup) and I believe it's ethanol free. I did notice that the same octane rating gas with MTBE gas.....my *fun factor* with the car seems to be better.

Is it just me or does ethanol gasoline decrease the car performance when comparing MTBE gasoline.

 

[Whimsey]

I've experienced the same thing when using gas with ethanol. My seat of the pants power feels weaker and my gas mileage is lower. Unfortunately I think NJ is also going to all ethanol additive in the near future.

Whimsey

 

[darkdan]

I did extensive testing with both 87 (non-ethanol) and 89 (15% ethanol) when I lived in Iowa. I never noticed a measureable difference in mileage that wasn't attributed to something else (weather, driving, etc).

Ethanol is a great cleaner too. So your engine is going to stay cleaner.

It's renewable, decently affordable, good for your fuel system, and better than oxygenated gas and other stuff IMO.

I swear, everyone else's butt must be more sensitive than mine. Everyone's always talking about throttle response and seat of the pants feel, but I can never notice a difference. That stupid log book of mpg is ruining my natural senses of detecting a change of 1 hp.

 

[Whimsey]

I dunna know

. Maybe the few gasolines sold with ethanol in NJ are "not the best" examples of ethanol blended gasoline. Especially since the majority of the gas currently sold in the state uses MTBE. Unlike in the midwest where ethanol is used mostly if not exclusively. I do know that if I use gasoline that has no oxygenators I get better mileage than gas with MTBE, which gets better mileage than gas with ethanol.

Whimsey

 

[Horatio]

My Civic seems to run better on 10% ethanol according to my butt-dyno. Mileage does suffer a little, though.

I'd heard about it being a good cleaner which is one of the reasons I've been using it.

Greg

 

[T-Keith]

Ethanol turns to varnish in a short period of time. It's terrible for small engines, as it gums up their carbs and fuel systems. Almost every problem I've seen with snowblowers and lawnmower has been caused by ethenal gas. All gas in MN contains about 10% ethanol by law, with the exeption of a few select pumps.

-T

 

[drm7]

I thought I heard years ago when ethanol was first added to gas that a byproduct of burning alcohol was water. Does anyone know if this added water to the combustion leads to rust or any other ill effects?

 

[darkdan]

10% really? I didn't know that. I haven't seen any stickers on the pumps like I'm used to in Iowa.

 

[DavoNF]

quote:

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Originally posted by drm7:
I thought I heard years ago when ethanol was first added to gas that a byproduct of burning alcohol was water. Does anyone know if this added water to the combustion leads to rust or any other ill effects?

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Gasoline also has water as a by product of combustion.

Ethanol has a low calorific value, compared to gasoline, so you are getting less "bang for the buck" when using an ethanol blend.

Some calorific value of fuels:

Petrol 50kJ/g
Deisel 45kJ/g
Ethanol 30kJ/g


Dave

 

[MolaKule]

I find that 10% ethanol in my Nissan 2.4L daily driver gives me more "pep' and acceleration than does 87 or even 91 octane.

Now our Nissan Pathfinder 3.5L V-6 doesn't show any preferences to ethanol fuel.

 

[ALS]

My Volvo doesn't care whether I use ethanol or not. Now my old 65 GTO 389 Tripower loved the stuff. It ran better on the 10% ethanol than straight 93 Premium.

 

[DavoNF]

quote:

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Is it just me or does ethanol gasoline decrease the car performance when comparing MTBE gasoline.

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chefwong,

Ethanol has a low calorific value, compared to gasoline, so you are getting less "bang for the buck" when using an ethanol blend.

Some calorific value of fuels:

Petrol 50kJ/g
Deisel 45kJ/g
Ethanol 30kJ/g


Dave

 

[T-Keith]

quote:

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Originally posted by darkdan:
10% really? I didn't know that. I haven't seen any stickers on the pumps like I'm used to in Iowa.

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Yes and it doesn't have to be labeled either, because they all are. MN was one of the first states to go all ethenol.

A few of local classic car clubs lobbied and got a select few non-ethenal pumps installed, these are labeled.


-T

 

[n8wvi]

In Michigan, if it's got ethanol in it, it must be labeled as such. Very few stations in SW Michigan have ethanol OR MTBE in them. When we travel to Chicago, I make sure to fill up before we leave so I don't have to buy the crap they sell there.

Dave

 

[MNgopher]

T-Keith is correct that all gas sold in MN is 10% ethanol, with the exception of select retailers who sell non-oxy premium for engines that require it.

The law went into affect in 1996. Thus, pumps in MN are not required to say 10% ethanol, it is just assumed.

I haven't has any problems with later model small engines using ethanol gas. Maybe it has to do with actually draining them dry before the off season?

 

[darkdan]

Ran to Iowa today. Fair weather conditions. Started using FP so maybe that had something to do with it.

87 octane with 10% ethanol and I got 34.7 mpg.
87 with no ethanol (return trip) I got 32.8 mpg.

Maybe there was a little wind (doubtful). I did the same speed both ways. Like I said, maybe the FP effected it somehow.

I understand on paper that ethanol is supposed to reduce fuel economy, but maybe my engine got used to it.

 

[DEWFPO]

Ethanol has 65% of the btu's per gallon as neet gasoline.

MtBE has 81% of the btu's.

You can calculate the power loss at any given percentage.

10% Ethanol gets you 96.5% of the power and MtBE gets you 98.1 % of the power.

The added oxygen molecules in the the MtBE and the Ethanol will help some fatter(richer) running engines run a little cleaner(more complete combustion) and perhaps even generate a little better mpg. But a late model, properly set up engine will get slightly less mpg and virtually no improvement in emissions.

DEWFPO

 

[GT Mike]

My 3800 non supercharged V6 was used as a Ginuea pig for 10% ethanol 89 octane gasoline, and in scanning certain parameters, I found my long term fuel trim (LTFT) went from near 0% to +3.5%, indicating that the engine was requiring 3.5% more fuel than the PCM had learned was correct before filling up.
I also measured knock retard (KR) at wide open throttle on a 2nd gear pull to redline and found that there was little to no difference in the amount of KR on this brand of 89 than there was on the previous tank of 87 without ethanol.
As a control, I filled up again with a tankful of 89 octane non-ethanol, and the KR did get reduced by about 2-3 degrees on an average WOT pull.

Fuel mileage was pretty consistent...I didn't really notice a severe drop in MPG. If anything, maybe I lost 1 MPG if that much.

Bottom line,
Since my tests showed that it takes more fuel to produce identical performance to that of regular 87, I'm not going to bother with ethanol enriched gasoline in my cars. There's no point in paying more for something that does nothing for performance (and may even reduce it) just to say I'm protection the environment.

I'd put my catalytic convertor back on if it mattered that much to me.

 

[Shannow]

quote:

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Originally posted by ALS:
My Volvo doesn't care whether I use ethanol or not. Now my old 65 GTO 389 Tripower loved the stuff. It ran better on the 10% ethanol than straight 93 Premium.

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ALS,
back when I was mucking around with Ethanol and other stuff, I found that if I put 5 litres of Metho, a cup of Acetone (co-solvent), and topped it up with leaded "super" it felt a lot crisper. Tweek the timing and it was even better.

Running a car with an O2 sensor didn't change much performance wise.

I think that the old "fun" cars with their rich jetting and big accelerator pumps loved the blends, as it brought them closer to spot on.

 

[mikep]

quote:

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Originally posted by darkdan:
I swear, everyone else's butt must be more sensitive than mine. Everyone's always talking about throttle response and seat of the pants feel, but I can never notice a difference. That stupid log book of mpg is ruining my natural senses of detecting a change of 1 hp.

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