johnand

+1. That must have been monumentally crappy gas (cheap hooch )to get ping on a MB.

LILBENZ230

I can run my Kompressor engine on 87 octane without any drivability problems. Power is reduced in the hot weather enough to notice it but not enough to really matter. In cooler weather at night it isn't noticeable. Gas mileage takes a 1-2mpg hit, though so it isn't ultimately worth it.

DrgnflyZ28

Well guys, the pinging occured at low speed WOT with BP/Amoco 89.
I did have the same issue when advancing the timing 5% on my Z28 (LS1 engine) with Amoco 93. I went with Chevron 93 and the pinging almost completely went away. I dialed in a 5% increase of fuel at WOT with 5% timing along with Chevron 93 with success in the hottest of summer days. This also includes a 160 degree thermostat and the fans kicking in at 190.

Glyn M Ruck

Yes, I believe you - Low speed knock is easily heard if unusual on Benz vehicles. Presume it was just a short rattle until the ECU retarded the timing? You could also have had a tank of winter fuel on a hot day. US Gasoline is not the best, nowhere near European quality, but their octane ratings (AKI) are extremely honest if it came from a major which it did.

LILBENZ230

So the M272 has a compression ratio of 11.4 and the M271 is 8.7.. but since it's supercharged it's higher? I don't understand CR stuff will someone explain what happens to the CR during boost on the M271?

Glyn M Ruck

The minute you apply forced induction to an engine you require to reduce CR to prevent detonation & other potential problems. Long subject! You have far greater volumetric efficiency & are depending less on capacity or RPM for power.

EDIT:

Matt here is a good basic article on forced induction including both TC's & parasitic blowers - Goes right back to Gottlieb Daimler

http://www.enginebasics.com/Advanced...Induction.html

Enjoy reading! Saves me having to think, illustrate etc.

Beepbeep

All this talk about E85 this and E85 that makes want to try it already. But I have to wait 'till the P0012 is fixed first.

aigooalex

i actually learned a lot by just posting up e85 haha =)
my gas mileage does suck compared to usual 91 octane cause thats all we got in Socal!
but the E85 has better performance no doubt. When i filled up the car, there was no sluggish start or anything. just smooth sailing from there!
i just wish there were more e85 carrying stations in Socal cause it's very limited =( but the drive of 10 miles to get the gas around my neighborhood doesn't hurt and at 2.69 a gallon compared to 3.25-3.35 for 91. i think it's a steal!

LILBENZ230

Thanks Glyn

Capt Nemo o2

Ok, so I did some more research on this... It turns out the its basically a crap shoot! Some cars see a slight improvement on E85, about 5-7 HP, while other cars see a drop in power. Even identical cars had differing results.

Maybe your butt-dynos are more accurate than mine, but I've never been able to feel a difference of 5 to 7 HP. Maybe its just that I'm used to bigger HP jumps, and the small ones seem trivial to me?!

Also, apparently the octane rating is not what people are told. The 105 is an average between pure ethanol at 85% and **** gas (the gasoline blended in has an octane less than what is available at the pump, to save money) at 15%. It could be more, it could be less, depending on the blend (Summer 85/15, winter 70/30). As there is no standard for E85 octane, they can say it is whatever they want it to be. But it seems people are getting their numbers mixed up, and it seems people are interchanging RON, MON, and AKI (which is what we use in the US). According to a report I found in an SAE (Society of Automotive Engineers) research paper, the RON, MON, and AKI of E85 is 101.5, 90.1, and 95.8. So therefore, E85 actually has an octane rating of 96. I personally will tend to believe what the SAE says as they set pretty much every automotive standard... And I happen to be a member... Never go against the family!

Now that being said, I wish (always did) that the M271 could run E85, just for the cooling effect the fuel has. It makes a much bigger difference on a FI car than on a NA car. Its built in water injection!

It would also be interesting to see an MB tuner mill the heads of a flex fuel engine to get higher compression and set up a tune specifically for E85. It would probably be one of the more simpler jobs to do, having to work the heads is a whole lot easier than boring the block... And it would look stock too!

johnand

Easily fixed by replacing the magnet for the camshaft control solenoid: https://mbworld.org/forums/c-class-w...-bank-1-a.html

Glyn M Ruck

Yes - I'm also a member of SAE & they are the gold standard - I'm also a member of NLGI & STLE plus numerous institutes of tribology. Anybody who has read my other threads on alcohols & Octane will note that I have always stated that alcohols as an octane booster have a low influence on MON - Motor Octane Number. See W204 forum mainly.

An AKI of 96 will allow useful tuning of a M272 engine.

Remember when Benz is talking octane requirements for their cars they are referring to RON - As stated on European pumps & those of most of ROW.

I personally think that the American AKI system is the best out there at the moment. I think we would all like to see MON on pumps as the standard as it is closest to reality. i.e. actual octane rating seen by a variable compression lab engine. The oil industry does not want this because it takes time and holds up blending of fuels in a refinery so they want RON as the standard.

The other problem is that real life engines all react very differently to Octane which tends to skittle the MON argument. Octane requirement of an engine is not only driven by CR & octane requirement changes as engines foul themselves.

Glyn M Ruck

Right - so you now understand that the CR remains constant at 8.7 but the volumetric efficiency is radically increased & you don't have to rely on RPM for power.

DrgnflyZ28

Keep in mind the peak HP gains you are referring to might not be felt that easily at WOT max revs but the advanced timing throughout the torque curve is where you will notice the most increase. Low end and and midrange torque under load is a tangible measurement for the butt-o-meter!
I do like your idea of milled heads, higher CR and an E85 tune!

Capt Nemo o2

Actually, according to the report, there was a big difference from regular to 10% and 50% but very little between 50% and 85%.

At least in the US, they dont make the NASA mistake and mix their units! They use the AKI numbers as "posted octane 91" followed by "(Avg. of 96 RON/86 MON). At least thats what it says in my manual!

Glyn M Ruck

You are talking of one report & not making a comparison with other findings/octane boosters.

After 39 years in the oil industry I stick to my guns that when compared with other octane boosters a broad range of short to long chain alcohols at any %age achieve less in the way of boosting MON than other common compounds used by the industry. This is well documented. Their is always a greater spread in RON vs MON with alcohols present.

I lived in Dallas & the Bay Area for many years. In fact I've just returned from a 2 month trip to the US so I'm not ignorant of what goes on, on your side of the pond & our company headquarters are today in San Ramon CA - not difficult to work out which company.

Yes - Benz finally got their act together regarding owners manuals reflecting the USA AKI situation. There is nevertheless a large, probably majority pool of Benz vehicles in the US that state RON on the fuel flap as was the norm globally. In international DB Technical literature they standardise on RON.

You are quick to say "that's not true!" - You have not justified this statement in any way. You are welcome to go on arguing with yourself.

I am quite satisfied that nothing I have posted is in anyway misleading or overstated.

Go and discuss the issue at the next SAE meeting with one of their highly competent members. I'm sure you would find their response enlightening.

I also suggest that you stop digging away at John Anderson - he is one of the highly respected engineers on this forum. Unlike you he does not publish it.

Capt Nemo o2

I don't know what you're talking about! I haven't disagreed with you! I'm only talking about Ethanol, not other alcohols or octane boosters. This thread is about E85, nothing else.

I now realize my statement about the difference between regular gas and different ethanol blends in my previous post may have been misleading to some. What I meant to say was that surprisingly there was a bigger difference when changing from regular 87, to E10, and E50 than there was going from E50 to E85, as in the change in octane was non linear. I agreed with you that ethanol is not a great octane booster, especially compared to the most widely accepted value of 105. This report, through testing, found that its actually 96.


As far as the what MB states, at least in the last 11 years, in the US they are stating AKI, not RON or MON. I know for a fact that the 1999 E320 we had clearly stated AKI. It would be a liablity for MB to mention otherwise as AKI has been the standard here, and posting otherwise would lead to confusion amongst consumers. If they were stating RON, people would be going around looking for 96 octane fuel. Yes, in technical papers, RON is used. I know that. However, the general public never sees that, and in the US most don't even know what RON and MON is. I don't even know why you are getting all pissy about this in the first place. If I was talking about a technical paper put out by MB, than I can agree with you, they are most likely talking about RON. But we are talking about what MB states on the car. Everywhere else its RON, but here in the US its AKI and it has been for quite some time.


And I'm not attacking anyone. I already stated that it is possible to get some extra HP just by switching to E85. I followed that up by saying that to me, I never was able to feel a few HP difference. That to me, to be able to feel a change in HP in the car, it would need to be a bigger change, say upwards of 15 to 20hp. To me, this is what I thought he was saying, that there was a night and day difference. And by the way, I have discussed this with the some officers of the SAE in 2008 at a powertrain confrence that me and other students went to. Some of the other students were working on converting a jetski to E85 for a project, and we got into quite a lengthy discussion about this amongst other things.

I never said that anything was "not true." I feel that it was quite rude and arrogant of you to go and personally attack me, especially after I stated that I was partially wrong, and that it is possible that his car gained a few HP. Some cars gain, some don't, even if they are identical cars. So while his car may have gained, its possible that other members here lost. Its also been found on this forum, that small gains felt are sometimes all in the head. We get people going on and on that putting on a new cat-back exhaust gave a "noticeable" gain, when it turns out that they actually lost power. Maybe this is why I was never able to feel these slight gains. When talking about such small gains, I need tangible proof. It's like temperature, I can't feel a one or two degree difference, I can feel a 10 degree difference though. So in closing, if you are going to attack someone, at least be certain they aren't on your side.

Glyn M Ruck

Excellent! - drop it - I strongly suggest you go back to the beginning of this thread & read what you wrote. BTW. I drove a Bremen built W204 in Dallas 4 weeks ago with a 95RON sticker on the fuel door. Benz have not had their act together over there. There are plently of W203s with RON stickers on them.

Capt Nemo o2

Just went back and reread the whole thread, and I don't see where you say I attacked someone, or told them they were out right wrong. I saw were I said that I don't think they made a lot more power, but it was also followed up with me stating I may be wrong. As it turns out, our definitions of "more power" were different, and I corrected myself. Please point it out to me. I'm not an arrogant *** that doesn't admit when I'm wrong, as is clearly pointed out in this thread.

As far as the RON sticker, in my experience, I have never seen one any Mercedes. Even on friends older MB cars from early 90's and 80's, the manual states AKI. I've never actually seen a number posted on the gas door, only "Premium Unleaded Fuel Only". The only place I have seen a number posted is in the manual, like I said earlier. Actually, I've never seen any car that posted the number on the fuel door or cap. Both of my Acura's, our old Infiniti Q45, the E320, and E500, and my friends Volvo and Lexus all say "Premium Unleaded Fuel Only" or something of that nature, no number. I would give other examples but I don't have access to any other cars that require premium fuel.

If someone does have a number on their car, whether AKI or RON, can you post a quick picture? Please prove me wrong, as I personally have never seen it.

And I still dont understand why you got your panties all bunched up and became so defensive when I never disagreed with you in the first place. As you stated earlier, this is an international forum, with people discussing based on their various experiences. I was speaking from my experience, and never stated anyone as wrong, or anything as fact, other than the findings I found in two reports, one by the University of Nebraska, and one in an SAE paper that was sponsored by the US Department of Enregy at the Oak Ridge National Laboratory. I clearly stated in my posts, that these facts came from reports from credible sources, and were not of my own. If I offended you in any way, I'm sorry, that was not my intentions. You took my posts differently, as I didn't see anywhere were I took attacks on anyone, told them that they were wrong, or in any aggressive, confrontational or offensive matter. I was clearly having a discussion. It's unfortunate that you felt otherwise. Your attack on me was clearly unwarranted.

Glyn M Ruck

Please stop being a sensitive flower. If you can't detect that you were being an irritation to John & I then so be it.

Write it off to cultural differences.

W203E35

I was told I need a Flux Capacitor to be able to run E85. I ordered the Flux Capacitor and filled up with E85 and when I reach 80mph still nothing

What am I doing wrong?

Thanks

Glyn M Ruck

Karo old sport - You must sell the Flux Capacitor to Patrick - then you should enjoy the full benefits of E85

You & Patrick might find another use for it in the back seat

Beepbeep

Thanks, John. My car is already in the shop today and should be done tomorrow. If the MB shop can't fix it right, I may do it myself with the instructions from your thread.

Ron

W203E35

I haven't seen Patrick for a while. After he sold me a DVD rewinder he doesn't return my calls. I rewinded a DVD and I think it messed up my DVD player because now any DVD that I watch after I am done it rewinds on it's own.




No more back seat action. Patrick sold his car and disappeared. Couple of the members can't get in contact with him including myself. I believe he is ignoring us. Not the first time so I am not worried about his safety and well being. Wish him luck in whatever crowd he likes to join. It was great knowing him for a year but Patrick is no more a friend in my book. Sorry Patrick but how many bridges can you burn??

Glyn M Ruck

Hmm! This Patrick seems to be a slippery character