E85
Super Moderator
Joined: Dec 2006
Posts: 2,403
Likes: 64
From: Camas, WA
2007 C230SS; 2014 ML350 BT
What do you want to know about it? I have run well over 100 tanks of the stuff.
For me, I get a 21% reduction in fuel economy, but in my area E85 is readily available and runs 35-40% less in cost than premium. Since I drive 25-30K miles per year, that is a significant savings.
With all the latest flashes for the ECM and TCM, the car runs pretty damn good on E85. Can take a second or 2 longer to startup than premium at times.
I also feel a decent increase in performance, as it is 105 octane.
I have done oil analysis and the Mobil 1 0W-40 Euro oil has no issues running exclusively E85 for the 13K service interval.
The station that I get mine at, gets it's E85 from the recently started cellulose based E85 refinery, so that is a much more environmentally friendly E85 than standard corn based if you care about such things.
For me, I get a 21% reduction in fuel economy, but in my area E85 is readily available and runs 35-40% less in cost than premium. Since I drive 25-30K miles per year, that is a significant savings.
With all the latest flashes for the ECM and TCM, the car runs pretty damn good on E85. Can take a second or 2 longer to startup than premium at times.
I also feel a decent increase in performance, as it is 105 octane.
I have done oil analysis and the Mobil 1 0W-40 Euro oil has no issues running exclusively E85 for the 13K service interval.
The station that I get mine at, gets it's E85 from the recently started cellulose based E85 refinery, so that is a much more environmentally friendly E85 than standard corn based if you care about such things.
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Senior Member
Joined: Nov 2008
Posts: 461
Likes: 0
From: Orange County, CA
C230 K Coupe (05)
What do you want to know about it? I have run well over 100 tanks of the stuff.
For me, I get a 21% reduction in fuel economy, but in my area E85 is readily available and runs 35-40% less in cost than premium. Since I drive 25-30K miles per year, that is a significant savings.
With all the latest flashes for the ECM and TCM, the car runs pretty damn good on E85. Can take a second or 2 longer to startup than premium at times.
I also feel a decent increase in performance, as it is 105 octane.
I have done oil analysis and the Mobil 1 0W-40 Euro oil has no issues running exclusively E85 for the 13K service interval.
The station that I get mine at, gets it's E85 from the recently started cellulose based E85 refinery, so that is a much more environmentally friendly E85 than standard corn based if you care about such things.
For me, I get a 21% reduction in fuel economy, but in my area E85 is readily available and runs 35-40% less in cost than premium. Since I drive 25-30K miles per year, that is a significant savings.
With all the latest flashes for the ECM and TCM, the car runs pretty damn good on E85. Can take a second or 2 longer to startup than premium at times.
I also feel a decent increase in performance, as it is 105 octane.
I have done oil analysis and the Mobil 1 0W-40 Euro oil has no issues running exclusively E85 for the 13K service interval.
The station that I get mine at, gets it's E85 from the recently started cellulose based E85 refinery, so that is a much more environmentally friendly E85 than standard corn based if you care about such things.
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,238
Likes: 0
From: Long Island, New York
'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
I'm going to have to say that this is probably all in your mind. Unless an engine is designed to run on high octane fuel, ie: extreme boost or high compression, its not going to give any more power. You can get a little more power by advancing the timing, but the ECU will not advance more than what it is set for running on 93 octane.
Now, if you are running in extreme heat, to the point where you are getting detonation on regular 93 octane, E85 will restore the power lost. However, the one thing that could actually add power is the fact that E85 uses so much more fuel, it actually cools the intake air a little bit, but I doubt its noticeable on a NA car. It would be more noticeable on a FI car, kind of like methanol/water injection.
Now that E85 is available on LI, I tried to convince my dad to set up the Cobra to run on E85. The only thing we would have to change is the carb (more CFMs) and a smaller pulley on the supercharger, as we have a fuel pump designed for 2000hp, and we just changed the fuel lines to a bigger SS lines for more fuel, as we maxed out the original fuel lines! Even though the extra power would be useless, its cool for the bragging rights.
Now, if you are running in extreme heat, to the point where you are getting detonation on regular 93 octane, E85 will restore the power lost. However, the one thing that could actually add power is the fact that E85 uses so much more fuel, it actually cools the intake air a little bit, but I doubt its noticeable on a NA car. It would be more noticeable on a FI car, kind of like methanol/water injection.
Now that E85 is available on LI, I tried to convince my dad to set up the Cobra to run on E85. The only thing we would have to change is the carb (more CFMs) and a smaller pulley on the supercharger, as we have a fuel pump designed for 2000hp, and we just changed the fuel lines to a bigger SS lines for more fuel, as we maxed out the original fuel lines! Even though the extra power would be useless, its cool for the bragging rights.
Last edited by Capt Nemo o2; Jul 26, 2010 at 02:23 PM.
MBWorld Fanatic!
Joined: Jun 2009
Posts: 1,833
Likes: 2
From: Queens, Ny
Nike Turbo Shox
I'm going to have to say that this is probably all in your mind. Unless an engine is designed to run on high octane fuel, ie: extreme boost or high compression, its not going to give any more power. You can get a little more power by advancing the timing, but the ECU will not advance more than what it is set for running on 93 octane.
Now, if you are running in extreme heat, to the point where you are getting detonation on regular 93 octane, E85 will restore the power lost. However, the one thing that could actually add power is the fact that E85 uses so much more fuel, it actually cools the intake air a little bit, but I doubt its noticeable on a NA car. It would be more noticeable on a FI car, kind of like methanol/water injection.
Now that E85 is available on LI, I tried to convince my dad to set up the Cobra to run on E85. The only thing we would have to change is the carb (more CFMs) and a smaller pulley on the supercharger, as we have a fuel pump designed for 2000hp, and we just changed the fuel lines to a bigger SS lines for more fuel, as we maxed out the original fuel lines! Even though the extra power would be useless, its cool for the bragging rights.
Now, if you are running in extreme heat, to the point where you are getting detonation on regular 93 octane, E85 will restore the power lost. However, the one thing that could actually add power is the fact that E85 uses so much more fuel, it actually cools the intake air a little bit, but I doubt its noticeable on a NA car. It would be more noticeable on a FI car, kind of like methanol/water injection.
Now that E85 is available on LI, I tried to convince my dad to set up the Cobra to run on E85. The only thing we would have to change is the carb (more CFMs) and a smaller pulley on the supercharger, as we have a fuel pump designed for 2000hp, and we just changed the fuel lines to a bigger SS lines for more fuel, as we maxed out the original fuel lines! Even though the extra power would be useless, its cool for the bragging rights.
Super Member
Joined: Jul 2008
Posts: 929
Likes: 3
From: Portland, Oregon
2016 GLE 350
My 2004 MY C240 is Flex Fuel compliant right out of the box. No set-up or special preparation needed, short of a few recomendations on fuel levels, running the engine for at least five mins after switching, etc when switching from gas to E85. Not sure if all Benz engines carry the FFV rating or not for the 04 MY, but the mighty 
2.6L V6 does.
2.6L V6 does.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
You just change fuel - that's all!
PLEASE do not run E85 in none Flex fuel cars - It will attack elastomers in the fuel system & cause corrosion.
PLEASE do not run E85 in none Flex fuel cars - It will attack elastomers in the fuel system & cause corrosion.
Junior Member
Joined: Jul 2010
Posts: 59
Likes: 0
From: NoVa
2007 C230, S2000
Now where is that gas station...
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,238
Likes: 0
From: Long Island, New York
'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
That wont matter! By the time that takes effect, the engine will have blown up from running too lean. Most non E85 compatible engines don't have fuel systems that can handle the extra fuel required!
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Most Benz engines will run just fine on Alcohols & are more than capable of adjusting AF ratio adequately. It's alcohol proofing of the fuel system that is the real issue.
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,238
Likes: 0
From: Long Island, New York
'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
As far as Benz engines adjusting, that's not true! Most MB engines are flex fuel compatible, but those that aren't may not be able to. If I recall, some M271 guys couldn't get enough fuel to compensate for the lean condition at high rpm's after putting in an overdrive pulley for the supercharger. This required no where near the extra fuel needed to run E85. They went as far as putting in new injectors, FPR, etc.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
I come from the petroleum industry & had a global job. I've been involved in testing Benz engines on the dyno from Brazil to using Sasol heavy alcohols in SA. Most Benz engines will be fine. You have picked on one engine that I can believe in the US state of tune might run into trouble at high RPM. The M271 in C180 & C200 tune will run OK - we've tried it. In C230 tune with the bigger blower (& especially if you overspeed that blower) you might tip it over the edge due to borderline injector sizes/capacity at high RPM.
Model Eng capacity Compression ratio Power Torque
180 Kompressor 1796 cc 10.0 : 1 143hp @ 5200rpm 162 lbft @ 2500rpm
200 Kompressor 1796 cc 9.3 : 1 163hp @ 5500rpm 177 lbft @ 3000rpm
200 CGI 1796 cc 10.3 : 1 170hp @ 5300rpm 184 lbft @ 3000rpm
230 Kompressor 1796 cc 8.5 : 1 192hp @ 5800rpm 192 lbft @ 3500-4000rpm
Most W204's in US are not fitted with Flex fuel systems. C230 2.5 V6's to the US were flex fuel. It's likely that most M111 & M271 were not flex fuel in the US - hence my warning. In ROW the American spec M271 engine was only fitted to a short run of Coupe's before they were moved to the 2.5l V6.
Model Eng capacity Compression ratio Power Torque
180 Kompressor 1796 cc 10.0 : 1 143hp @ 5200rpm 162 lbft @ 2500rpm
200 Kompressor 1796 cc 9.3 : 1 163hp @ 5500rpm 177 lbft @ 3000rpm
200 CGI 1796 cc 10.3 : 1 170hp @ 5300rpm 184 lbft @ 3000rpm
230 Kompressor 1796 cc 8.5 : 1 192hp @ 5800rpm 192 lbft @ 3500-4000rpm
Most W204's in US are not fitted with Flex fuel systems. C230 2.5 V6's to the US were flex fuel. It's likely that most M111 & M271 were not flex fuel in the US - hence my warning. In ROW the American spec M271 engine was only fitted to a short run of Coupe's before they were moved to the 2.5l V6.
Last edited by Glyn M Ruck; Jul 27, 2010 at 07:56 AM.
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,238
Likes: 0
From: Long Island, New York
'05 C230SS 6MT, 1966 Triumph TR4a IRS, Shelby Cobra 427 Supercharged
I come from the petroleum industry & had a global job. I've been involved in testing Benz engines on the dyno from Brazil to using Sasol heavy alcohols in SA. Most Benz engines will be fine. You have picked on one engine that I can believe in the US state of tune might run into trouble at high RPM. The M271 in C180 & C200 tune will run OK - we've tried it. In C230 tune with the bigger blower (& especially if you overspeed that blower) you might tip it over the edge due to borderline injector sizes/capacity at high RPM.
Model Eng capacity Compression ratio Power Torque
180 Kompressor 1796 cc 10.0 : 1 143hp @ 5200rpm 162 lbft @ 2500rpm
200 Kompressor 1796 cc 9.3 : 1 163hp @ 5500rpm 177 lbft @ 3000rpm
200 CGI 1796 cc 10.3 : 1 170hp @ 5300rpm 184 lbft @ 3000rpm
230 Kompressor 1796 cc 8.5 : 1 192hp @ 5800rpm 192 lbft @ 3500-4000rpm
Most W204's in US are not fitted with Flex fuel systems. C230 2.5 V6's to the US were flex fuel. It's likely that most M111 & M271 were not flex fuel in the US - hence my warning. In ROW the American spec M271 engine was only fitted to a short run of Coupe's before they were moved to the 2.5l V6.
Model Eng capacity Compression ratio Power Torque
180 Kompressor 1796 cc 10.0 : 1 143hp @ 5200rpm 162 lbft @ 2500rpm
200 Kompressor 1796 cc 9.3 : 1 163hp @ 5500rpm 177 lbft @ 3000rpm
200 CGI 1796 cc 10.3 : 1 170hp @ 5300rpm 184 lbft @ 3000rpm
230 Kompressor 1796 cc 8.5 : 1 192hp @ 5800rpm 192 lbft @ 3500-4000rpm
Most W204's in US are not fitted with Flex fuel systems. C230 2.5 V6's to the US were flex fuel. It's likely that most M111 & M271 were not flex fuel in the US - hence my warning. In ROW the American spec M271 engine was only fitted to a short run of Coupe's before they were moved to the 2.5l V6.
