# Fuel Specification - Regular vs. Super vs. Super Plus



## PanEuropean (Nov 3, 2001)

Hi All:
I just finished a road trip from Zurich to Berlin to Dresden and back to Zurich - about 1,800 kms (1,200 miles) total. I couldn't find a Phaeton to rent, and because I had three other adults traveling with me, I didn't want to rent an Eos, so I rented a Passat wagon. It had a 2.0 liter gasoline engine in it.
I wasn't all that impressed with how well the car accelerated during the first 500 kms of driving. By this, I mean it got up to speed, but it took forever to get to speed, and when I was accelerating from medium to high speeds (100 km/h to 180 km/h, or 60 MPH to 110 MPH), the thing always shifted down one or two gears. No torque.
When I stopped to fill the car up, I was quite surprised to find a sticker inside the gas cap that specified "Super Plus" - that being 98 RON fuel, which is about equal to 94 on the North American scale (R+M)/2. I was surprised because the W12 engine in my Phaeton only requires 95 RON (91 American), and the owner manual says it will run quite well but with slightly reduced power on 91 RON (87 American). Anyway, because my employer was paying the gas bills, I grabbed the expensive pump handle - the 98 RON stuff, which was the highest of the three grades offered, and filled the car up with that.
I didn't notice a whole lot of difference during the next tankful, but once I got to Berlin, the tank was close to empty (setting 100 MPH on the cruise control with 4 guys and luggage kind of does that), and I filled up again with the 98 RON stuff. Wow, did that ever make a difference on the trip back! The car accelerated better, the engine made less noise, and when I wanted to accelerate from medium to high speeds (again, from 100 km/h up to 180 or so), the car did it without complaining and without shifting down.
I know that many of the Eos being sold in NAR have 2.0 liter engines in them. I don't know if it is the same engine as the 06 Passat that I had over the weekend, but, my suggestion is that you have a close look at what kind of fuel is specified on the sticker inside the gas cap, and put the right stuff into the car. Chances are, the 'right stuff' won't be regular. The difference in performance between regular (what I presume the last rental user put in it) and super plus is both significant and noticeable - and not just at the higher speeds, either. The car was quieter, smoother, and quicker off stoplights on the way back, after having been fed a few tankfuls of what it was supposed to get fed.
Michael


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## PanEuropean (Nov 3, 2001)

*Re: Fuel Specification - Regular vs. Super vs. Super Plus (PanEuropean)*

FYI, there are two photos below. The first one is the fuel specification sticker from my Canadian car (Phaeton with W12 engine). Disregard the numbers on that so far as an Eos is concerned, the only reason I have posted that picture is because it shows you the difference between European fuel ratings (RON) and North American fuel ratings ((R+M)/2).
The lower of the two pictures is from an Eos I found in Berlin. It is possible - in fact, it is probable - that this car has a different kind of 2.0 engine in it than the NAR Eos, simply due to emission compliance differences. What is worth noting, though, is that the Eos sticker shown below is the same as the sticker on the Passat I had over the weekend - it *wants *to be fed 98 RON (about equal to 94 American), and it will *put up with *being fed 95 RON (about equal to 91 American), but it won't run right on anything less than that.
Michael
*W12 Fuel Sticker (just to show the two measurement methods)*

*Eos 2.0 Fuel Sticker - European Car*


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## ialonso (Aug 26, 2006)

Someone please figure it out, but I think 98 RON is close to 93 (R+M)/2, which is widely available in the US. (At least in the South)
From Wiki (I know it's not the most reliable source in the world, but it comes up quick in the search !)
http://en.wikipedia.org/wiki/Octane_rating
In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above,* this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-95 (regular) in Europe.*


_Modified by ialonso at 6:04 PM 11-27-2006_


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## just4fun (Oct 29, 2006)

*Re: Fuel Specification - Regular vs. Super vs. Super Plus (PanEuropean)*

In Canada this could pose some interesting difficulties for some people.
I'll admit I haven't paid a whole lot of attention to Octane ratings lately, but I believe most premium fuel in Canada is 91 Octane.
Some stations are starting to offer 'super premium" fuels rated at 93-94 octane, but my search on the web indicated that these products are currently only available at select retailers in the major centers. (Toronto, Montreal, Vancouver)
My web search didn't locate a single retailer offering super premium in Alberta (imagine that, smack dab in the middle of oil country, no high end fuel?? go figure)
This is not to say it _isn't_ available out there, just that my web search has indicated it could be difficult to find in certain areas.
This may explain some of the comments on the forum about the 2.0T not being very spunky, while all the reviews tout it as being a very adequate engine.
Keep an eye on the ethanol blended fuels, apparently they have the potential to have slightly higher octane ratings.(the ethanol used to blend with gas has an octane rating of 118, but the end product depends what they are blending it with in the first place)








Kevin


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## ChicagoVW (Sep 10, 2006)

*Octane*

OK, now I'm utterly confused. When I go to the gas station to buy gas, I get three choices: Regular Unleaded, Mid-Grade, and Premium. I'm assuming that I'm going to have buy Premium, but I have no idea (without running to the gas station right now) as to what the octane number if for premium gas. Is U.S. premium gas a high enough octane for the 2.0T engine? Or will I have go searching for "Super Premium"????








Alex


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## darien (Oct 28, 2006)

*Re: Octane (ChicagoVW)*

If I am not mistaken, the most common levels of octane are 87 (regular), 89 (mid-grade) and 93-91 (premium) here in the States. 


_Modified by darien at 7:18 PM 11-27-2006_


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## cb391 (Mar 12, 2006)

*Re: Fuel Specification - Regular vs. Super vs. Super Plus (PanEuropean)*

Michael,
I suspect the Passat you had probably had the 2.0L turbo engine like the Passat gets for use in the U.S. I believe it is the same engine used in the Eos. It does require the use of Premium grade fuel. Either you got bad gas or someone else filled it with wrong or bad gas and it took a few tankfuls of good/correct gas to make the car run better.


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## cb391 (Mar 12, 2006)

*Re: Octane (ChicagoVW)*

Alex,
If you stick with the major brands and use their "Premium" grade(min of 91 octane rating) you should be just fine. It may seem like a lot extra to pay but it is worth it. By the way, how was the Eos on your trip?
Andy

_Modified by cb391 at 9:21 PM 11-27-2006_


_Modified by cb391 at 9:22 PM 11-27-2006_


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## bougy (Nov 21, 2006)

*Re: Octane (cb391)*

Michael,
I know you are a brilliant forum and hitech addict (I'm sure you're a electronica/mechanical engineer), but don't you think that a car riding at 180km/h for 10 hours is going better afterwards because of this strong engine clean up (the exhaust pipe must be white afterwards).
For the kickdown, if it was a DSG, probably that the fuzzy logic didn't allow the car to shift down of 2 gears at the end : if you are riding only in highway at constant speed withtout demanding a kickdown often and the fact that the torque is not spend in a "dirty" engine anymore.
Of course, 98oct is giving you more power with the 2.0T (see ABT or Oettinger motor tuning with their Intelligent Management : 91oct : 200hp, 95oct : 220hp and 98oct 240hp (as far as I remember))
Bougy


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## ChicagoVW (Sep 10, 2006)

*Re: Octane (cb391)*

Thanks for clarifying, and thank you fo rasking. As a matter of fact, I'm still waiting on my car. Supposed to get it today. It's been sitting at the rail yard in West Chicago for 11 days. So I didn't get to take it on the road trip and have missed almost all of this amazing warm weather.






















Alex


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## gilesrulz (Nov 2, 2006)

*Re: Fuel Specification - Regular vs. Super vs. Super Plus (PanEuropean)*

The sticker inside the cap says 91 or 95, But I've been putting 87 in mine most of the time, and have noticed no drop in performance. It's just as peppy as it ever was. I've also noticed no gain in performance when I use premium (93 around here). Of course I don't think I've used more than one tank of premium before filling up with regular, so I guess I'll try that this time.
I have to say though, putting more pep in this car is wholly unnecesary!


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## Grinder (Feb 6, 2004)

The previous renter probably put the cheapest fuel in the vehicle when filling up the tank prior to retuning it to the rental shop. On my 1.8t passat (2003 I could 89 octane but the engine would detune; having a full car and driving 100mph would be the one of the few times that I could potentially notice that. Sunoco in Ontario sells 94 octane but closed up shop in our city.


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## PanEuropean (Nov 3, 2001)

*Re: (ialonso)*


_Quote, originally posted by *ialonso* »_Someone please figure it out, but I think 98 RON is close to 93 (R+M)/2, which is widely available in the US.

Hi Israel:
I think you are correct in your assessment. When I was trying to figure out how to convert the European fuel performance rating to a North American fuel performance rating, I did a fair amout of looking... then figured out that it would probably be simplest just to use the same conversion factor that VW uses, which is an offset of 4 between the two figures. This can be seen on the fuel sticker on my car, which shows 95 and 91 as the two acceptable European flavours of fuel, and 91 and 87 (in each case, 4 units less) as the two acceptable flavours of North American fuel.
What surprised me is that the newer, smaller engines - such as the 2 liter engine - require a significantly higher octane rating than the older, bigger engines such as my W12. Also, looking at the fuel specification sticker for the European Eos (top of the thread), the owner is *not *given the option of using any fuel with a lower octane rating than 95 (European), which is equal to 91 American. I am sure the engine will start and run on a lower octane rating of fuel, but it will probably go into a significantly reduced performance mode. 
I do recall that I once filled up my Swiss Golf (1.6 liter engine) with really, really low octane fuel while driving through the Czech Republic a few years ago. I can't remember what the octane rating was, but I think it was something like 89 or 87 European (equal to about 85 or 83 American) - a flavour that was only available in the former Eastern bloc countries to support really old Eastern bloc cars. Anyway, after about 5 miles of driving, the Golf got really sick and practically spat the fuel out of the gas tank - the CEL (Check Engine Light) came on, and the car went into 'limp-home-mode'. It took another 500 miles of driving to flush all the crap fuel out of the tank, and get the car back to normal operation again. It's funny to look back on it, but it wasn't funny at the time - the car struggled to reach 100 km/h (60 MPH).
Michael
*How VW does the fuel conversions*
_note the difference of 4 units between European and American measurement systems_

*Important PS! -  The above sticker is not from an Eos! It is from my Phaeton, which uses lower octane fuel than an Eos. I only posted it to show how the octane conversions are done. Do NOT use it as guidance for what octane to put in your Eos.* Michael


_Modified by PanEuropean at 11:19 AM 11-28-2006_


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## PanEuropean (Nov 3, 2001)

*Re: Octane (bougy)*


_Quote, originally posted by *bougy* »_...I'm sure you're a electronic/mechanical engineer..

Thanks for the compliment, but that is not the case at all. I am an aircraft pilot and aircraft maintenance engineer by training, and presently work as an Aviation Safety Manager.
Michael


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## gilesrulz (Nov 2, 2006)

*Re: (PanEuropean)*


_Quote, originally posted by *PanEuropean* »_
What surprised me is that the newer, smaller engines - such as the 2 liter engine - require a significantly higher octane rating than the older, bigger engines such as my W12. Also, looking at the fuel specification sticker for the European Eos (top of the thread), the owner is *not *given the option of using any fuel with a lower octane rating than 95 (European), which is equal to 91 American. I am sure the engine will start and run on a lower octane rating of fuel, but it will probably go into a significantly reduced performance mode.

I think I read somewhere that it's because it's an FSI engine that it wants higher octane fuel. Something to do with the fact that they are more efficient that way, but like I said, I have burned 87 in mine to no ill effect.


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## just4fun (Oct 29, 2006)

*Re: Fuel Specification - Regular vs. Super vs. Super Plus (just4fun)*


_Quote, originally posted by *just4fun* »_In Canada this could pose some interesting difficulties for some people.

Some good news for (some of) us Alberta drivers.
First, upon reading Micheals original post again, the fuel ratings recommend 98 RON or 94 Octane as the preferred fuel, but also show 95 RON or 91 Octane as acceptable as well. So for the most part, premium fuel purchased just about anywhere in NA should be OK to run in the EOS.
Second, upon further research, select Husky / Mowhawk stations in Calgary (5 locations) and Edmonton (3 locations and one in Stoney Plain) sell Performance Plus 94 fuel. But unless you are lucky enough to live near one of the stations that carry it, you will have to drive to find it.
Unfortunately the rest of Alberta is out of luck for the higher octane fuel at this time.
Here is a link for a station finder for Husky/Mowhawk.
http://www.myhusky.ca/locator/index.php
Petro Canada also sells a 94 octane super premium fuel, but only in BC and Quebec. I haven't found any information confirming whether or not Shell or Esso sell a 94 octane product.
Gilesrulz has confirmed he is satisfied with the performance of his EOS on 87 octane, and if you are really concerned, you can always pick up some octane booster at an auto supply store and add it to your fuel, as per the directions.







Kevin


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## cb391 (Mar 12, 2006)

*Re: (gilesrulz)*

It is not only due to being FSI but probably more due to the fact that the 2.0 has the turbo. All the cars I can remember that have a TURBOcharger (or a supercharger) require premium fuel. The current line of engine controllers will allow the use of lesser fuels but "detunes" the engine so it puts out less performance AND also prevents the engine from "knocking". My guess is you drive the car primarily with one or maybe two in the car and very little extra cargo. This may not be enough load on the engine when using regular to affect performance. If you start driving up steep grades with four adults and some luggage, you will notice a difference. Also running lower octane fuels in hot weather may cause the engine to want to try to keep running when you turn the key to off. This condition, called "run-on" or "dieseling" is NOT good for the engine. The fuel filler door on my Eos says to use minimum octane rating of 91 and though I don't like paying a "premium" for my fuel I do it to prevent the bad things that could happen.


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## cb391 (Mar 12, 2006)

*Re: Octane (ChicagoVW)*

That stinks. Mine sat there only 2 or 3 days. If you didn't get it today I'm sure your dealer will be hearing from you. I don't think there is any reason your car should be there that long. 
Andy


_Modified by cb391 at 8:16 PM 11-28-2006_


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## BigFoot-74205 (Jan 26, 2006)

*Re: (cb391)*


_Quote, originally posted by *cb391* »_It is not only due to being FSI but probably more due to the fact that the 2.0 has the turbo. 

Well I've got the NA 2.0 FSI engine in my Eos and it also requires 98RON (94 octane) fuel just like the 2.0TFSI engine.


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## just4fun (Oct 29, 2006)

*Re: (cb391)*


_Quote, originally posted by *cb391* »_It is not only due to being FSI 

Does anyone know the compression ratio on the 2.0 / 2.0T??
When you're pushing 200hp out of a 2.0 litre engine there has to be many performance "enhancements" made by the manufacture.
The turbo is one example, extra valves, valve positioning, valve timing, injector pattern, injkector timing,...... etc, etc. 
Higher compression ratios are also common. Generally speaking higher compression ratios require higher octane fuels to prevent "run on" or "dieseling" as mentioned above.
I suspect the recommended higher octane is quite simply because, considering the size of the engine, this is a high performance mill.
The onboard computers can detune the engine so it will likely run OK without damaging the engine on lower octane fuel, but if you want to take full advantage of all the performance engineering that went into the design of the engine, you will want to use higher octane fuels.
IMHO







Kevin
PS Just check out a hot rod forum, these guys that tweak their cars for max performance have lots of threads talking about where to get high octane fuels, in some cases even using diluted aviation fuel for octane numbers around 100.


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## gilesrulz (Nov 2, 2006)

*Re: (just4fun)*

I have actually been doing some research on this, as I was curious why it wanted higher octane fuels and what the damage would be from lower octane fuels.
The results are that the reason that the 2.0TFSI wants higher octane fuel is indeed because it uses a 12.0 : 1 compression ratio, which would be more efficient with higher octane fuels. 
However, Marc Trahan, Director of Audi Product Management and Quality said "We recommend premium fuel, but it can operate on regular. It simply won't realize the maximum performance potential."


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## chrisj428 (Feb 26, 2005)

*Re: (cb391)*


_Quote, originally posted by *cb391* »_though I don't like paying a "premium" for my fuel

Principle is usually a very precarious perch on which to stand.
Let's do the math...
Let's say, for the sake of discussion, every time you fill up, you're putting 16 gallons in the tank. Now, the delta between the cost of regular and premium typically floats at around $0.20/gallon. This means, in reality, it's costing $3.20 more per tank.
Now, let's say you drive a lot and go through a tank of gas a week, which, assuming you're averaging 375 miles out of a tank (about 23 mpg on average, and these get much more than that with normal driving), means you're driving about 19,500 miles per year. That's 52 tanks of gas, times $3.20 per tank, which works out to $166.40 per year additional. 
So, with a very "worst case" scenario, assuming you drive 130% more than average and are only getting abou 80% of the average fuel economy, it's costing you $13.86 extra a month to give the $30,000 to $40,000 investment you made the appropriate fuel.
Having said that, now that we've removed the additional cost of premium fuel over regular fuel from the argument, why *wouldn't* you feed your vehicle the correct fuel & take care of it they way it deserves???


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## PanEuropean (Nov 3, 2001)

*Re: (chrisj428)*

I have to agree, Chris makes a very good point.
We did sort of a 'group experiment' in the Phaeton forum last year amongst the owners who have the W12 engine. The W12 engine is designed to run on either regular or super fuel (91 American or 87 American). The owner manual notes that the engine will not make full horsepower if you put regular grade in it, but that's not a big concern - if it only makes 90% of the 420 horsepower it is capable of, that will be enough to get you from home to the grocery store and back.
Anyway - what we discovered was that the car didn't accelerate as quickly (in other words, it didn't react to stomping the gas pedal as fast) when it was being run on regular grade, and fuel economy was fractionally lower when running on regular grade. The end result of this was that most of us (including myself) who had been running on the 87 octane switched back to using the 91 octane. I made a trip about a month ago from Toronto down to Florida and back, using only the highest octane fuels that were sold, and I was very happy with the 'get up and go' that the car demonstrated.
It's interesting to note that Phaeton owners who have the V8 engine (the 4.2 liter one) are not given the option of using a lower grade of gasoline. The specification sticker for the V8 says 'put premium in it', exactly like the Eos sticker does.
The trick to getting the very best mileage (disregarding all the usual stuff, like driving style) is to avoid the fuels that have ethanol in them. Ethanol has a lower calorific value than petroleum distillates, but we pay the same price for it as we do for gasoline that is 100% pure petroleum. The volumetric quantity of fuel that that the engine consumes will vary according to the energy content (calorific value) of the fuel. I just can't see the logic of paying the same price for a fuel that has (for example) 85% petroleum distillates and 15% corn distillates as I do for fuel that has 100% petroleum distillates. Heck, it's like paying the same price per liter for a bottle of wine as you pay for a bottle of scotch. It's pretty clear that for a given unit of volume, the wine has less kick to it than the scotch does.








Michael


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## gilesrulz (Nov 2, 2006)

*Re: (PanEuropean)*

While I too agree that much of our gas buying decisions are completely irrational when compared to the way we purchase other things. For example we might drive two miles to save 2 cents a gallon on gasoline, but wouldn't even cross the street to save the same 20 cents on a gallon of milk.
However my I have two problems with your arguments. One is that you are comparing the fuel consumption of two VERY different engines when you compare the 2.0T to your W12. I'm not sure there can be any conclusions drawn from your experience with 12 cylinder standard injection engine that would be relevant to a four cylinder FSI engine.
Second, while fuels with ethanol in them may not have the same calorific value of pure petroleum fuels, these concerns seem to be greatly overshadowed by the environmental benefit these ethanol mixes provide.


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## PanEuropean (Nov 3, 2001)

*Re: (gilesrulz)*


_Quote, originally posted by *gilesrulz* »_...while fuels with ethanol in them may not have the same calorific value of pure petroleum fuels, these concerns seem to be greatly overshadowed by the environmental benefit these ethanol mixes provide.

Hi Giles:
What I am not sure about is whether ethanol actually offers any environmental benefit or not. I say this honestly, because I'm not well educated about the subject.
When you burn something - be it gasoline, ethanol, natural gas, or even 100% pure biodiesel - you are still releasing CO2 into the atmosphere, and I think CO2 emissions are the current 'hot button' amongst the environmentalists.
I thought that the (supposed) big advantage of ethanol is that it is a home-grown fuel - "made in America" and all that - and it was supposed to reduce American dependance on oil imports.
Here in Europe, where plain old regular grade gasoline costs well north of USD $7 per gallon, there is virtually no use of ethanol at all... and I think that in general, Europeans are much more 'environmentally responsible' than North Americans. By way of example, we have deposits on plastic bottles to ensure that they are all returned, and in my village, we have to pay a tax of about USD $3 per garbage bag that we leave out at the curb for pickup. You can bet that kind of tax encourages recycling, not buying disposable stuff, etc.
I kind of think that the whole ethanol deal in the United States (and recently Canada, too) is just enriching the pockets of the farmers who grow the corn, and the politicians that they elect. But, like I said, I'm not really well educated on the whole issue.
Michael


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## chrisj428 (Feb 26, 2005)

*Re: (PanEuropean)*


_Quote, originally posted by *PanEuropean* »_When you burn something - be it gasoline, ethanol, natural gas, or even 100% pure biodiesel - you are still releasing CO2 into the atmosphere, and I think CO2 emissions are the current 'hot button' amongst the environmentalists.

Not to hijack the thread & go off on a tangent, but...








CO2 is indeed the hot-button in Europe and most of the rest of the free world.
In the NAR, the major concerns are NOx and HC -- the reasons why diesels have such a difficult time getting through the EPA. 
While you're correct that ethanol, most likely, has a negligible impact on CO2 emissions, I believe it does have an impact on the other two -- which is why it was introduced into "winter blend" fuels (along with the MTBE train-wreck, since discontinued) and has found its way into year-round "boutique" blends for markets like Chicagoland.
E85, on the other hand is a political and/or "feel good" purchase and makes as much sense economically as a hybrid. (There. I said it.







)


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## gilesrulz (Nov 2, 2006)

*Re: (PanEuropean)*

I would gather that the lack of ethanol in Europe is really more of an indicator of how little corn is grown there than anything else.
Here are some fun facts for you!

_Quote »_ * Reduces tailpipe carbon monoxide emissions by as much as 30 percent
* Reduces exhaust volatile organic compounds (VOC) emissions by 12 percent
* Reduces toxic emissions by 30 percent
* Reduces particulate matter (PM) emissions by more than 25 percent

Ethanol has been around for 50 years, if the the politicians are getting rich by anyone, it's by the oil companies that have made considerable efforts to keep it out of the main stream. And for that matter the farmers in this country could certainly use a little enriching. The family farm is increasingly going out of business in the US because small farms can't turn a profit.


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## vweosdriver (Oct 30, 2006)

*Re: (gilesrulz)*

According to some articles you forgot one, about 30% less MPG when using 85% ethanol mixture.


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## cb391 (Mar 12, 2006)

*Re: (PanEuropean)*

Ethanol is one by-product of trying for cleaner emissions in the US(possibly elsewhere). Before federal requirements, lead in gasoline was the norm. Lead was used to boost octane ratings and also helped lubricate valves and valve seating. It also caused most of the white exhaust pipe syndrome. Lead also ended up coming from the tailpipe. When the US went to unleaded fuel they went to other chemical compounds to make up the difference in octane. Other internal redesigns of valve train followed. Finally the concept of ethanol came about. Ethanol is higher octane than gas but was less efficient. What the ethanol provided was octane boost and extra oxygen molecules to help the gasoline burn better. Also it caused less engine deposits and of course required less gasoline. We will likely have ethanol gasoline (E-10 and others) until something better comes along.
As for why some engines burn premium and others regular has to do with performance requirement. Smaller displacement engines require more modifying to get more horsepower. This often involves increasing Compression ratios which requires premium fuel. VW requires premium for the 3.2L and 3.6L V6 engines and for the 4.2L V8. They have compression ratios of 11.0:1 to 12.0:1. The Eos even though listed at 10.3:1 requires premium because the turbo causes the same effect as raising compression. Your W12 with 12 cylinders can get away with slightly lower compression ratio simply because it has more cylinders to share the work.


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## cb391 (Mar 12, 2006)

*Re: (BigFoot-74205)*

Can't speak for European market, but in the US (and Canada, I think) the Eos comes in 2.0 and Eos 2.0T. The only difference is content level. Both have the Turbo and both require premium fuel. I suspect if you recheck you owner's manual it may say the engine has turbo.


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## cb391 (Mar 12, 2006)

*Re: (just4fun)*

According to what VW is listing on vw.com it is listed as 10.3:1. This is so they have more headroom for the turbo.


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## cb391 (Mar 12, 2006)

*Re: (chrisj428)*

I would like to say I'm sorry if I was complaining about the price difference. I'm still going to treat my car the way VW intended. Ive done the price comparisons and you are correct. It still is cheaper to drive than my second choice and just as much fun....


_Modified by cb391 at 2:39 PM 11-29-2006_


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## chrisj428 (Feb 26, 2005)

*Re: (cb391)*


_Quote, originally posted by *cb391* »_I would like to say I'm sorry if I was complaining about the price difference. I'm still going to treat my car the way VW intended. Ive done the price comparisons and you are correct. It still is cheaper to drive than my second choice and just as much fun....

Oh my goodness -- no need to apologize. I get on my soapbox sometimes when either the drama llama or the dead horse rears its ugly head.


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## just4fun (Oct 29, 2006)

*Re: (vweosdriver)*


_Quote, originally posted by *vweosdriver* »_According to some articles you forgot one, about 30% less MPG when using 85% ethanol mixture.

Ethanol has approx. 18% less energy in it than petroluem gasoline. But since it is commonly only 10% and more recently sometimes as high as 15% of the total product, the actual total reduction of energy in the fuel mix is around 1.8% to 2.7%. (2%-3% for discussion sake)
Without clouding the issue by involving physics or chemistry, mostly because I'm totally unqualified to do so, lets assume there is a direct correlation between fuel energy and fuel economy.
Therefore a vehicle that gets 30 mpg would see a theoretical reduction of fuel economy of between 2 or 3%, or 0.5 to 1 mpg.
Any reduction is worth taking into consideration, but I don't believe it would be as drastic as a 30% reduction.
Here are a couple links to learn everything you never wanted to know about Ethanol fuels
http://www.eere.energy.gov/afd....html
http://www.myhusky.ca/husky_fo....html







Kevin


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## vweosdriver (Oct 30, 2006)

*Re: (just4fun)*

I'm only quoting the observed actual results in auto magazines reviews for the 85/15 mixture. YMMV


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## just4fun (Oct 29, 2006)

*Re: (vweosdriver)*


_Quote, originally posted by *vweosdriver* »_I'm only quoting the observed actual results in auto magazines reviews for the 85/15 mixture. YMMV

I hope you didn't take offense to my reply, that certainly wasn't the intent. I also have no doubt that those figures were published in articles.
Just to clarify as well, I'm neither pro nor con on ethanol blends, just enjoying participating in the discussion.
I personally have never seen results published showing such drastic reductions in fuel economy and wonder if perhaps it was an unintentional misprint by the author. You would think if ethanol blends reduced fuel economy by such a large margin they would have disappeared off the market years ago because no one would buy the product.







Kevin


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## just4fun (Oct 29, 2006)

*Re: (vweosdriver)*


_Quote, originally posted by *vweosdriver* »_I'm only quoting the observed actual results in auto magazines reviews for the 85/15 mixture. YMMV

Hi vweosdriver,
Should ask you for a quick clarification if you don't mind.
Are the articles you refer to discussing 85% ethanol 15% petroleum, or 85% petroleum 15% ethanol?
As far as I know the 85% ethanol blends are not widely available yet because they require engines specifically designed for burning that type of fuel.
I have been refering to the more commonly available 85-90% petroleum and 10-15% ethanol blends.
With a low percentage of ethanol in the fuel, I wouldn't expect to see such drastic reductions in fuel economy, however on an 85% ethanol blend those results could very well be accurate.







Kevin


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## tdiindahaus (Jun 29, 2010)

Sorry for bringing this back from the dead, but I would like to say this is one of the most educational threads I've seen on VW Vortex. Just picked up a 2007 2.0T Passat and put 89 Octane in it. Ill be sure to put Premium 91 Octane on my next fill. Thanks guys and thanks Google for helping me find this thread lol... this should be a Sticky for the guys who go from TDI to Turbo gassers


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