one of my closest friends works for exxon mobile and is familiar with their ethanol testing. she informed me that even though it may cost less and have lower emissions... it burns less efficiently than petrol and you end up needing to fill up more often and buying more gas in the long run.

in my opinion.. if you want to reduce emissions, ride public transportation to work or ride a bike.

 

If you want to reduce emissions, ask Al Gore to land his private jet, and turn off some of the lights at his house. That would reduce them more than if you sold your car and stayed home.

 

Updated mileage log and charts (Check the 1st post).

I am getting 30.81% reduction in mileage running E85, which is spot on with the fact that E85 has 30% less BTU's/gal. E85 has dropped in price quite a bit here lately, so I am still roughly even for cost. (My logs show $.01/mile more to run E85.)

I did run into my 1st little issue. A few days ago when I 1st started the car, I got a fairly significant rough idle for about 20 seconds. Ambient temperature was roughly the same as it has been. The only thing I can think of that was different, was I had the car sitting in the driveway all day the day before, and before I went to bed, I started up the car and pulled it into the garage, so it ran for 30 seconds or less. Normally, I drive the car right into the garage, and don't have to do the extra short start.

I also did my 1st oil change and sent it in to analysis. I am curious to see how running E85 effects the oil.

 

Nice! You're very thorough with this. Thanks for the info.

 

Check the 1st post for updated mileage log, chart and Excel file. No real changes on mileage, etc.

Though, I have run the last 13 tanks on E85. I have noticed some crappy shifting from the 7G-tronic tranny for a while (I know that is somewhat the norm for the 7G, but mine has gotten worse since I bought it). I have had abrupt downshifts and some lack of downshifts on occasion. Today I filled up with Premium Unleaded and noticed the usual weird shifting has gone away So, I suspect that the 7G-tronic needs some better calibration when running on E85. Since my car has all the latest flashes, what can be done? I guess the only choice I have is to take it into the dealer and complain about the shifting on E85.

 

<<Oh, I just figured you'd be thrilled to see another "Official" thread. Just playin >>

A good friend who writes for a national car mag plus other bulletproof qualifications said to me last summer at a car club convention which shall remain nameless, "80% of the info on the web is BS and the other 20% is uniformed speculation."

Not my stuff of course, but I dunno about the rest of you guys.

Humor, you understand.

 

I tend to agree with that. But, I hope that wasn't directed at me or my posts. Being an engineer, I pride myself on technical information and accuracy of that information. That is part of the reason I started this thread and a number of other technical based threads. You can take a look at my spreadsheet, I made it as detailed and accurate as I possibly could. I think gas mileage figures that people discuss on forums are far from accurate. I think people tend to "fudge" their mileage figures quite a bit. No, I don't have any hard evidence (like dyno) that the car has more power with E85, that is just my observations, best as I can describe.

To get this thread back on track, I will post updated files tomorrow. I now have almost 13K miles and 575 gallons of fuel data to report.

 

Did you ever get the oil analysis?

 

Yes, I did. It is posted in my oil analysis thread. Here is the post of the results: https://mbworld.org/forums/showpost....9&postcount=22

As you can see the results are very good!

 

I have been having some cold start issues this week and suspect it is an issue with E85. Temps have been in the high 30's to low 40's. When the car has sat all day (8hrs) at work, the last 2 days have had the following problems starting.

I went to start the car, it fired immediately, then stumbled for a second and died. The second start was more of the same. The 3rd start fired, had a rough idle for a few seconds, then ran just fine. I suspect the gas station I am getting my E85 from is running the summer blend of E85, and hasn't switched to the E70 yet. But, all the research I have done, says you shouldn't see cold start problems with E85 until temps in the 20's and below.

I filled up with premium this morning and will monitor startups to see if the problem goes away with premium gas. I had the latest ECM software as of my last service visit (About 4 months ago.) Not sure if there are any updates out.

 

That is a bit unnerving. Did you check for any OBD Codes?

E

 

I would have if my DAMN neighbor would have returned my AutoXray that I loaned him a few weeks ago. Once I get it back, I'll scan and report back here.

 

Only 320 automatics are compatible. C320 6 speeds are not compatible.

 

Any update?

 

I recently pumped E85 on my 07 C class and there was a noticable change in acceleration and power! There are acouple of stations near me house, now my question is... Does it affect the car if I mix E85 with 91? Say I havent finished all the gas in my tank and I pump another gas type? Just wondering.

 

The owner's manual clearly recommends against mixing them! If you are going to change from one to the other, it is best to do it with 1/4 tank of fuel or less. The ECM will run on any mix of E85 and premium, but it runs best with all premium or all E85.

Haven't ran E85 in my car in a while. The cost difference lately has not been great enough to make up for the loss in MPG.

 

This a flex-fuel car, I hope. If not, you are in for trouble when you don't know what you are doing.

In a flex-fuel model like my '08 C300, every single component that is touched by the fuel is a different material than the non flex-fuel models. For example, the fuel tanks are a different type plastic that won't be destroyed by the ethanol.

Your owner's manual describes how and when you can switch back and forth.

 

The 2007 C230s were flex-fuel vehicles.

 

I know my car is fuel flex, i can pump E85 but I was just concerned about switching over..

 

Only those years? I have a 2002 2.6L C240 luxury series, will it work on E85 fuel?

(Old thread, I know. But RON95 is over 30% more expensive than E85 now in Sweden. Also planning for the Mad Max-future where I can destille my own fuel )