My experience on using 0% ethanol 93 gasoline

[Rajmun340]

My M3 used 10% ethanol 93 gas ever since BMW delivered it to me from factory 2 years ago. Today for the first time i experimented on a full tank of ethanol free 93 gas from a BP station. I waited until i was driving on the reserve to get rid of most of my previous gas. I had probably only 12.5% of E10 gas left. After filling up i should be close to pure gasoline.

Here are my raw feelings on driving the car for the next 1 hour highway and city driving.

- Is this my car or what ??? Wow. Engine freed up a lot. Throttle response improved, picking up speed is stealthier (more on that below). The engine does not seem to be battling the fuel, it works seamlessly. Engine feels much more refined and better balanced.

- The sound is different. I got very accustomed to my engine sound when running E10 and I noticed after running ethanol free that gurgling (guttural) sounds in mid throttle are gone replaced by a much more pleasant jet like engine sound with more deep bass is how i can best describe it.

- Engine runs noticeably smoother in lower gears which makes the car much more fun to drive. It will change your appreciation of the car.

- I paid 25% higher price tag - $3.27/gal compared to premium E10 cost $2.6/gal at the same BP station - but that is not how you do the comparison you have to compare your mileage. I usually get 16 mpg on E10 in my city/hwy driving. I reset the onboard mpg calculator and over one hour after filling up i watched the mpg number while driving spirited. I crept up from 17, 18, .. all the way to 21 and stayed there and i was doing some accelerations noticeable by other drivers. That is a 23.5% improvement. So effectively i am only paying 1.5% more or 4 cents / gal for ethanol free 93.

The engine is much much happier there is no doubt about that. It seems it delivers with less effort so i find myself at faster speed without even lighting up the angry side of the engine.

[tkearns119]

I wish I could get 93 octane E0% close to me. Did find a pump with 90 octane E0% near me and like you, I did notice a very slight throttle response (not sure it was not a placebo effect) but did sound like the induction noise through the midrange RPMs was different. Ran 10 gallons 10 of 90 octane E0% and 5 gallons of E10% 93 octane. The E0% was a significant premium over local E10% $3.09/gal vs. $2.29/gal. Not sure it is worth it at that price difference.

[admranger]

Interesting. Let's see how things shake out over time.

The following is not personal commentary on you (or an attack), so please don't take it that way. However, to be totally objective we should consider the following:


For some real fun, give your credit card to a friend, let them fill your car up for you with one or the other and then see if you can discern a difference. Then do it again and see if you notice a difference or not. Double blind testing (or dyno testing) are objective tests. When you spend more $$$, you want to get "better" stuff. Plus, you expected better performance from the pure 93 than the 10% ethanol 93 and it's exactly what you got. Perfect example of "confirmation bias".

Again, not an attack on the OP or a statement of disbelief of his findings, just an objective way to look at this (and any other mod on your car).

FWIW, I believe the OP got better performance. Ethanol has less energy content than gasoline, that's not up for debate. I wonder how fast the ECU adapts to different fuels?

Hell, I wish I could get 10% ethanol 93 in Vegas at the pumps, but we can't because California. <sigh>

[kb9uwu]

All these amazing changes just from switching from E10/93 to E0/93? Dude, pass the joint my way!

[pbonsalb]

MPG takes a while to stabilize after reset. Ethanol is about 30% less efficient, so removing its 10% to fuel ratio is worth only a few % mpg improvement.

Butt dynos are of limited use. Would be interested in a real e10 93 vs straight 93 dyno. Doubtful any power differences sufficient enough to feel would show up.

[Flying Ace]

Originally Posted by admranger

Interesting. Let's see how things shake out over time.

The following is not personal commentary on you (or an attack), so please don't take it that way. However, to be totally objective we should consider the following:


For some real fun, give your credit card to a friend, let them fill your car up for you with one or the other and then see if you can discern a difference. Then do it again and see if you notice a difference or not. Double blind testing (or dyno testing) are objective tests. When you spend more $$$, you want to get "better" stuff. Plus, you expected better performance from the pure 93 than the 10% ethanol 93 and it's exactly what you got. Perfect example of "confirmation bias".

Again, not an attack on the OP or a statement of disbelief of his findings, just an objective way to look at this (and any other mod on your car).

FWIW, I believe the OP got better performance. Ethanol has less energy content than gasoline, that's not up for debate. I wonder how fast the ECU adapts to different fuels?

Hell, I wish I could get 10% ethanol 93 in Vegas at the pumps, but we can't because California. <sigh>

yep, I agree...confirmation bias is the first thing that came to mind. OP needs to do it many more times and control for residual amounts of fuel in the tank each time and see he correctly guessed more than 50% of the time.

I'm not attacking OP either, but I read that Michael Schumacher was able to tell whether a different fuel was used on his F1 race car. That's coming from a professional driver, consistently driving the same track, on the same day, on the same equipment, in the same conditions...

[Cidle]

I've experienced the opposite, tuned on 91 with ethanol, cause that's all that was available. Then dyno again at home few days later on 94 with no ethanol.

End result; had to take timing away

[Rajmun340]

Originally Posted by admranger

For some real fun, give your credit card to a friend, let them fill your car up for you with one or the other and then see if you can discern a difference. Then do it again and see if you notice a difference or not. Double blind testing (or dyno testing) are objective tests. When you spend more $$$, you want to get "better" stuff. Plus, you expected better performance from the pure 93 than the 10% ethanol 93 and it's exactly what you got. Perfect example of "confirmation bias".

Again, not an attack on the OP or a statement of disbelief of his findings, just an objective way to look at this (and any other mod on your car).

FWIW, I believe the OP got better performance. Ethanol has less energy content than gasoline, that's not up for debate. I wonder how fast the ECU adapts to different fuels?

Hell, I wish I could get 10% ethanol 93 in Vegas at the pumps, but we can't because California. <sigh>

I understand your angle but I got a steady 21 mpg in mix hwy / city driving improvement over my usual ~16 mpg on E10. I am going to continue to monitor it over time and give updates. FYI... for my car to get above 20 mpg on E10 previously was only possible on the hwy driving without any kind of enjoyment.

What is subjective is the words that I used to describe how the engine runs on E0 but there is no doubt at all, the difference is unmistakable for the driver. A double blind is not prescribed.

[Longboarder]

Interesting. On the dyno I made a little more power on 91 octane (e10) pump plus 2 gallons of e85 than I did on (ethanol free) MS109 race gas mixed with some pump gas to blend to 96-97 octane with maybe e5. I've experimented with a lot of different fuels and didn't notice any of the attributes the OP mentions about my car behaving any different with lower ethanol contents.

Too bad we can't get e0 93 in Cali. Heck we can't even get 93 octane.

[burtonsbs5114]

I have never used ethanol laced gas in my M3, and (knock on wood) have not experienced the gas related issues i have read about on this form. The only gas I have put into my car is BP 91 octane E0.

[Rajmun340]

Originally Posted by Longboarder

Interesting. On the dyno I made a little more power on 91 octane (e10) pump plus 2 gallons of e85 than I did on (ethanol free) MS109 race gas mixed with some pump gas to blend to 96-97 octane with maybe e5. I've experimented with a lot of different fuels and didn't notice any of the attributes the OP mentions about my car behaving any different with lower ethanol contents.

Too bad we can't get e0 93 in Cali. Heck we can't even get 93 octane.

I'm in NC, there are not that many stations that offer it. Mine came from a BP station. Usually E0 stations are in rural areas or around lakes. Apparently there is a steady flow of E0 customers for boating / lawn mower / landscaping engines.

My car is stock.

[Longboarder]

Originally Posted by JoeM3SSII

I'm in NC, there are not that many stations that offer it. Mine came from a BP station. Usually E0 stations are in rural areas or around lakes. Apparently there is a steady flow of E0 customers for boating / lawn mower / landscaping engines.

My car is stock.

Hey sounds like your car likes it. If I were you I would do something like 5 tanks of e0 93 and then go back to e10 93 and see if you feel a difference again.

[tkearns119]

Originally Posted by DrFerry

After going Harrop super charged, I have totally changed my opinion on this subject. Keep in mind the DME/ECU is seeing the signal input from the 02 sensors and knock sensors adjusting the air fuel ratios (AFRs) accordingly to hit the fuel trim targets in the tune file (or oem tune file). If I recall correctly, the ECU tries to achieve lambda = 1 (out of my depth here a bit) regardless of fuel or fuel blend by adjusting injector pulse width duty cycle. As Mike Benvo pointed out to me, "the ECU does not know what type of fuel is in the tank".

So, if the 02 sensors 'see' lean or rich AFRs, the ECU injector adjustments are made instantly - until the lambda = 1 target is reached (stochiometric air to fuel ratio for gas is 14.7:1 and for Ethanol its like ~9.0:1 I think). If the ECU hears knock then timing is retarded. Now since spark knock is effected by octane, I blend 2.5 gallons of E85 (105 octane) with the rest of the fuel being 93 octane E10 (10% ethanol) which yields about 95 octane. This allows the ECU to achieve the timing targets and fuel trim targets of the flash file without spark knock under hi boost.

The same would be true for non boosted cars. Though I do admit MPG will be worse. I'm doing the fuel blend because I can't get 95 octane 100% pure gas. Now without going into a lot more detail, of which there is a bunch more on this forum, in theory and practice, octane is the only thing that should be affecting hard acceleration performance (not MPG) and guarding against ignition timing being pulled if knock is sensed.

So, for me, and in my own tests, increasing octane is the key to all out stock M3 performance AND boosted M3 performance. In order to achieve the max timing targets and fuel trim pre programmed into the ECU flash file the M3 'needs' about 94.5 octane - even in non super charged cars. Keep in mind the S65 uses a 12:1 compression ratio. There is a lot of info out there on this subject.

Now perhaps E10% 93 RON versus E0% 93 RON is having some other tiny drivability affect on non super charged cars, but I have seen the opposite, and would never have seen it had I not gone SC and needed to blend fuels. I support what Longboarder's dyno test found.

Yes, ethanol does absorb water if you park your car for months at the airport in the rain, and it does map MPG worse BUT best of all it inhibits spark knock, and yields cooler combustion chamber temps. Okay, I'm off my soap box. I used to be a huge advocate of 100% pure gas in 93 RON, but now I am not especially if an E85 blend (2.5 gals) can yield >=95 octane.

Any issues running essentially E22.5%? Any concerns with the real octane calculation value of E85 being rated incorrectly high. That 105 listed is really closer to 94-96 according to some articles I have read.

[admranger]

Originally Posted by JoeM3SSII

I understand your angle but I got a steady 21 mpg in mix hwy / city driving improvement over my usual ~16 mpg on E10. I am going to continue to monitor it over time and give updates. FYI... for my car to get above 20 mpg on E10 previously was only possible on the hwy driving without any kind of enjoyment.

What is subjective is the words that I used to describe how the engine runs on E0 but there is no doubt at all, the difference is unmistakable for the driver. A double blind is not prescribed.

There are a nearly infinite number of variables on your highway drive from day to day. As suggested by others, let us know how things go after multiple tanks, then switch back for multiple tanks and see what happens. One data point isn't that statistically significant.

FWIW, I can get >21mpg (per OBC) per tankful cruising between Vegas and Phoenix or Tucson at some not so legal speeds and with aggressive 2 lane passing maneuvers. In the summer. With the AC on. No problem. If Phoenix traffic is iffy, then it can all go to heck very quickly and I'll stare at 18mpg all over again like on my daily commute.

[bigjae1976]

I've used E0 91 octane. I did get 3mpg more on that tank otherwise it ran the same.

E85 is not like regular gasoline grades since it is not regulated. Gasoline is tightly regulated by federal and state agencies for quality and emissions. So E85 may be E60, E90 or something else. Proceed with caution.

[DSilk]

The use of ethanol in fuel has nothing to do with energy conservation or clean air. It takes as much energy (and oil) to produce a gallon of corn-based ethanol as you can produce by burning it as fuel. The push to use it has everything to do with federal subsidies for corn. It is a travesty foisted upon us for absolutely no good reason, and it should be eliminated. Take away the subsidies and ethanol becomes less attractive economically than oil.

[kb9uwu]

Originally Posted by DSilk

The use of ethanol in fuel has nothing to do with energy conservation or clean air. It takes as much energy (and oil) to produce a gallon of corn-based ethanol as you can produce by burning it as fuel. The push to use it has everything to do with federal subsidies for corn. It is a travesty foisted upon us for absolutely no good reason, and it should be eliminated. Take away the subsidies and ethanol becomes less attractive economically than oil.

^This...

http://www.pure-gas.org/ is your friend.

No puregas above 87 around here, so E10/93 it is.

[tkearns119]

Originally Posted by DrFerry

I've run as high as ~E25.7 without issues. However, other folks on other threads have experienced limp mode when E30 is exceeded. Now perhaps that was because they had stock injectors which could not cope with the extra volume demanded to achieve lamda = 1, but I'm speculating and do not know for sure. Search for the other ethanol threads and you'll see ~E30 seems to be about the limit for stock oem configured M3s.

Thank you for pointing out that the octane rating of E85 may not be rated correctly. If I understand what I've googled correctly that issue is because some pumps labelled E85 may actually be E75 or E65. The pumps I use clearly say contains 85% ethanol for flex fuel vehicles. I posted a photo on one of the other ethanol threads. Anyway, even if the octane increase is incorrect sometimes due to seasonal fluctuations in the 15% gas contained within the E85 pump blend, the octane is still increased when blending. So for me, on a boosted car, more octane is better.. even if it might (might) be a bit less than calculated.

Can you perhaps post links to the articles saying E85 is really 94-96. Below is a photo of the pump I have access to. I'm lucky I can blend the fuel all at one pump and the E85 is shown as 85% ethanol and 105 RON.

See E85 thread:
http://www.m3post.com/forums/showthread.php?t=1011930

See page 29 under Octane.

http://www.ethanolrfa.org/wp-content...pdatedLogo.pdf

[kaede]

I have been using E10 gasoline and E0 gasoline consistently and i can tell you in the M3, it makes little to no noticeable difference in terms of power and efficiency.

I live in Canada, and the US border is only "quick" 20mins drive away from where i live. I used to visit US almost weekly to pick up items i purchased online at a post office when CAD is almost a parity with USD (I missed the good deals and the savings on cost of shipping a lot... CAD is super crappy now @0.7113 USD). When i am there, i always filled up at the local Shell/Chevron which only offered E10 92 octane. I track my fuel mileage on fuelly, and with doing that for almost two years, i averaged around 17mpg (i drive 90% city, 10% highway approximately).

When CAD turned into sh*t, i started fueling up locally at the Shell/Chevrons over here Canada side. Shell offers E0 91 octane and Chevron offer E0 94 octane at basically all the locations. Been putting in both of those for about year and a half now, and the fuelly tracker averaged around 17.5mpg. The better fuel economy could be due to many factors.

Power wise, many locals claims that Chevron E0 94 octane produces the best results, but i honestly cannot tell the difference at all whether on streets or track. As previously noted by another member reply, if you did consistent testing with the same vehicle, same track, same conditions, you might be able to slightly differentiate E0/E10 with the M3, but for DD, i really didn't see the difference.

HOWEVER, that is not to say that on some vehicles it makes a huge difference. On my previous tuned E90 335i, because of its boosted nature, running gas with E10 is preferred. Many ran it with mixture of E85 and yield much better results on dyno and track. Fuel economy obviously suffered due to the fact that it burns ethanol much faster.

On my garage queen a old 94' Acura NSX, i did similar tests as well to run E10 vs E0, and boy did the E0 make the car run "better" in terms of power. Older cars were never designed to run Ethanol, and the NSX loves pure gasoline much more and is quite noticeable in terms of power (could be placebo) and mileage. (get around 10%-15% more per tank based on fuelly!!).

Personally, i will run E0 if i had the choice because why not (unless cost is a concern). Chemically it produces more oomph than Ethanol mixed gas, and i never liked to idea of Ethanol in gasoline to begin with. Run a longer test as suggested by many and report back! Cheers! =D

[1MOREMOD]

I run e0 92 octane excusively in my track car. Seems slightly stronger but my data is lacking because other factors have changed also.

[Rajmun340]

** Update **

-cold starts: Driving off on very light throttle i was accustomed to some mild hesitations in 1st gear on a cold engine which i have easily learned to eliminate with the clutch. There were some mildly embarrassing moments when i was new to the car. Giving more gas or releasing the clutch avoids this (6MT). I have to go through a pedestrian area to the access the road or I may not have notice that. I never questioned this with E10 93 from day 1.
With E0 93, instantly gone ! After a cold start, the engine will not hesitate no matter how light the throttle pedal, even trying to induce the hesitations. For me this is solid improvement.

-I have not had a chance to test extended hwy mileage but given the 17 to 21 mpg jump for mixed driving, 25-26 mpg hwy may not be too far fetched.

-Car feels like it lost weight, no more sluggish sensations in suburban areas driving where I had to give minimum 1/2+ throttle to get what i want. On E10 the car is a Jekkil and Hyde, it's either lazy or angry not much in between. With E0 there is a continuum of responses, more resolution and definition not that threshold where you feel oh there it is.. the engine is much more cooperative and refined. Improved throttle response is definitively there. I can see how on a track this would be beneficial (1MOREMOD).

-

Originally Posted by kaede

Personally, i will run E0 if i had the choice because why not (unless cost is a concern). Chemically it produces more oomph than Ethanol mixed gas, and i never liked to idea of Ethanol in gasoline to begin with. Run a longer test as suggested by many and report back! Cheers! =D

Yes i'm going to follow Longboarder's suggestion and run 5 tanks of E0 93 then switch back. Gas prices are at an all times low !!

[Rajmun340]

Originally Posted by DrFerry

tkearns, thank you very much for the pdf document link. Excellent stuff. One of the keys to the octane rating of E85 posted on the pumps is it is derived from the Average Knock Index (AKI) = (RON + MON)/2. For ethanol, I found the following at hotrod.com = http://www.hotrod.com/how-to/engine/...ernative-fuel/
...

I would not gobble everything you read from that bio fuels pitched pdf (" funded through an educational grant from the Renewable Fuels Foundation"). Information will be cast with a pro-ethanol agenda, make no mistake. Aligned with the money.

People like us driving a performance car should be more circumspect and consult independent studies.