I have an '05 C230 Sport, which I presume is only suppose to run on premium, but a friend recently bought an '07 C230 Sport and on the inside of the fuel filler cap it says it can run on either premium or E85. What's your thoughts on the upside and downside of running E85. It is available at a nearby Shell station and is about $.60 gallon less than premium. Any performance differences? Don't know much about it and was wondering what the group thought. Thanks.

 

ONLY put E85 into your tank if your car is labeled that it accepts that fuel.

That said...E85 is a poor fuel. It offers significantly less amount of energy. It is also much less efficient. Your MPG will actually go down, and your performance will decrease quite a bit. The cost savings is actually going to me much much less, as you will have to buy more of E85 to get the same mileage out of 91 octane fuel. It's just a poor fuel in general ... it takes 2-3 times more energy and resources to produce it, and it's much less efficient in your vehicle.

Mercedes was politically correct for making your vehicle compliant with a bio-produced fuel, but it will run as it was designed for on premium, ie: more efficiently and perform better.

 

+1 - Stay away from E85 if you can. For starters Alcohols only really increase the Research Octane of gasoline and not the Motor Octane so the ECU is going to tend to run your timing retarded all the time if it detects knock. As Chris says it has lower density which = lower energy. It needs less air to fully combust because there is an oxygen molocule sitting there already. Compatibility with any copper (or other metals that act as a catalyst) containing alloys & metal parts, as well as elastomers in the fuel system is suspect.

Don't do it, especially in M271 engines that are fuel sensitive to start with in the cylinder head area. Benz have no option but to say it's OK but they can't be happy for engines designed to run on Eurograde 95+

 

Data and results on E85 consumption in johnand’s (a respected engineer) thread:

https://mbworld.org/forums/c-class-w203/194074-official-e85-ethanol-thread.html

 

I forgot about that thread. It's a good read.

 

Thanks - just read it all. Very well done and no surprises there.

I've plenty of experience of Brasil's ethanol problems over the years right back to VWs with carburettors where the alcohol would eat right through the carb body in the presence of water & low temp below the venturi. Ended up making carb body from pure zinc - guaranteed copper free! (no corrosion catalyst) & removed every brass component from the fuel system. It also stripped the ternplating out of their fuel tanks so they had to fit plastic ones. They also had to reformulate every elastomer used in the fuel system. Had similar problems in South Africa with Sasol long chain alcohols dosed into our gas at 10% until Sasol found a more lucrative market for them. These products also stripped off automotive paints of the day.

The Brasilians tolerate all sorts of driveability problems which you and I would not.

The high temperature stumbling that Johnand experienced is typical vapour lock and to be expected.

 

yeah i would stay with premium. I think generally the idea of burning food as a fuel source is a losing proposition. Only good thing about e85 is that it keeps money within the US instead sending it out foreign countries.

I would rather wait for the hydrogen fuel cells, i still think thats our best bet. I know India is planning on having hydrogen pumps through there country by 2020.

We in the US gotta get our butts in gear and stop wasting time on this e85 experiment.

Most new cars can take up to 15% alcohol in the system due to emission laws that require 15% alcohol in petro. But i would recommend against using e85 unless your car is generally certified to run it.

I know on the tuning side, lot of turbo guys use e85 because even though it has less potential energy, its high compression properties are similar to 110oct US. So its perfect for high boost applications.

 

Thank you all for your replies. I'll definitely advise my friend to stay away from E85. The comment that Mercedes did it for political purposes makes a lot of sense.

 

+1 Mike - Turning potential food into fuel is a loosing proposition unless you are Brasil who can produce more sugar than they can sell so they play the sugar alcohol game dependent on which earns the most. Thailand have now started doing the same thing that I had a hand in. Took a whole delegation from Thailand to Brasil in 2002 to show them how the Brasilians do it. The trouble is that apart from the Campinas area, Brasil is cutting down rain forest to grow cane. Something I don't approve of.

I'm interested in your comment on the tuning/turbo side. What is the claimed octane rating of your E85?. Alcohols usually give you a good research octane number - what is generally displayed on the pump around the world (although I think the US was at one time using a calculation between research & motor octane) - but not so good motor octane number - what the engine actually sees or responds to. This can lead to stumble knock but more importantly & more destructively to high speed knock which can do big damage to an engine if the ECU can't retard the timing sufficiently at the onset of knock & it's detection. ECU mapping frequently needs to be changed to accommodate this. Bosch standard mapping is generally unable to achieve sufficient retardation.

Some Ethanol & Methanol blends can be extremely high octane but are more expensive to produce & blend.

Aside from latent heat of evapouration issues with alcohols - directionally they - require less air for combustion because they are oxygenated - typically 9 to 1 air fuel ratio versus gasoline at 14 to 1 (not ultra lean burn engines) so they don't need excess air. Blown engines usually run lower compression ratios.

That said, with the higher volumetric efficiency of a blown engine you can provoke uncontrolled auto ignition - knock

So, I presume these guys are feeding a hell of a lot more fuel into these tuned engines so the consumption must be awful. Fine if you are looking for power but it defeats the E85 object somewhat? A vehicle thus tuned would probably not run OK on normal gasoline without adjustment.

 

Using e85 is more popular among the Japanese tuning crowd. Basically e85 is used as cheap substitute for race gas given that a lot of people don't have access to race gas and most of the time its double the price of premium.

quoted from the wiki, e85 has a US octane rating of 105-110, i think when converted its around 129 RONS. The higher octane rating allows turbo'ed cars to turn up the boost without having to worry about detonation.

http://en.wikipedia.org/wiki/E85

Most of these guys usually have standalone aftermarket ecu's where you can load multiple fuel maps via obdii port and a laptop. So you can have a tune for e85 for the track and have a tune for daily driving on regular petro.

US spec evo (evo fq 300 for you i believe) running e85 on a stock turbo running 10's

http://www.youtube.com/watch?v=Y1_G6UEYNYg

I looked into it briefly when i was going to go the turbo integra route and wanted a way to turn up the boost when i'm at the track.

Darin Dachiara has a 8second supra on e85. Its putting down around 800whp.



http://www.youtube.com/watch?v=v2a1dXiCbOw

http://www.youtube.com/watch?v=dxGAdVmxaA0

 

Thanks Mike - OK so this is real high octane stuff and the guys are using multi map ECUs. I wonder why they have so much octane giveaway? 129 RON 110 MON? (I speculate - it could be lower - see the huge difference between RON & MON!!!) when they could sell a cheaper blend at normal Octane even if they blended with gasoline & reduce the price. - Most interesting - I've just scanned this will digest in detail - thanks for educating me on the US aproach - different to elsewhere - In this case knock would be unlikely but other problems could manifest. If I had a M271 powered car I would not use it - I can't believe that the ECU mapping can be ideal - it has to be a compromise for many vehicles

 

That's because Brasilians tolerate all sorts of everyday life problems which you and I would not.

 

Yes true! Still a great country

 

Yeah the 129 rons i got off the wiki. There are other supporting mods you need other then fuel maps, i'm just too lazy to list them all. Like i said its mainly used as a cheap substitute for race gas given it can give similar peformance but is 60-70% cheaper.

http://en.wikipedia.org/wiki/Octane_rating

I think its a creative way of using a alternative fuel.

 

Yeah - I used to run my motocross team's bikes on methanol in my old Honda Racing days

 

There is a label on the Shell pump stating up to 10% Ethanol. Could that amount of ethanol cause future problems when used long term?

 

no because new cars are designed to take up to 10-15% of ethanol. if your in california or a state that follows california emission standards its already in all the gas.

 

I agree with Mike. The OEMs have it pretty much sorted for Gasohol
- The ECU map will tolerate 10 - 15% Ethanol
- Metal components in the fuel system have now been engineered to tolerate the corrosive effects of alcohols
- Elastomers (seals, pipes etc.) have been reformulated/respec'ed to tolerate ethanol & not shrink, swell or crack

I have two cautions, however.

- Keep the entire fuel system absolutely original. Do not allow the fitment of aftermarket pirate parts that may not tolerate alcohols. That includes filters which may use non alcohol friendly glues, sealants, epoxy's, media etc.
- Ensure you keep water away from the fuel at all costs. Water & gasohol are bad friends. Water will cause the alcohol to phase separate out of the base fuel. The alcohol is a partial Octane booster & your car could suffer knock running on the base fuel alone if you have a phase separation in your tank with the water/alcohol phase below your draw off point. The car will generally misbehave if there is enough water present due to fuel slopping around in the tank. Once water/alcohol mix hits the injectors it will stutter.

BMW was going to put a water sensor into the tanks of their cars with a light on the dashboard for Gasohol markets but shelved the idea. Why? - I don't know. I think it was an excellent idea

 

funny how we were talking about ethanol and turbo applications.

Looks like ford took a page out of the tuner handbook.

Looks like fords developing a ethanol boosted direct injection engine codenamed bobcat.

http://www.autoblog.com/

 

funny how we were talking about ethanol and turbo applications.

Looks like ford took a page out of the tuner handbook.

Looks like fords developing a ethanol boosted direct injection engine codenamed bobcat.

http://www.autoblog.com/

 

funny how we were talking about ethanol and turbo applications.

Looks like ford took a page out of the tuner handbook.

Looks like fords developing a ethanol boosted direct injection engine codenamed bobcat.

http://www.autoblog.com/

 

Fascinating! I really like the principle of keeping the ethanol separate and not blended

 

Boost is the future apparently. Looks like the swedes had it right all along.

 

One good thing about E85 is that it cleans out all the carbon in your engine. Maybe run a tank or two through every few thousand miles to keep the carbon build up at bay. Other than that, E85 is crap.

 

Yep! Benz run 2 turbo's on the Diesotto hybrid - 1 small, 1 large.