Official E85 (Ethanol) thread
in my opinion.. if you want to reduce emissions, ride public transportation to work or ride a bike.



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.
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.
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.
Last edited by johnand; Jul 16, 2007 at 04:42 PM. Reason: Message for moderator
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.
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.
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.
The Best of Mercedes & AMG
As you can see the results are very good!
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.
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.
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.
(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
)
Last edited by Jonas75; Jan 30, 2022 at 10:46 AM.




Once I get it back, I'll scan and report back here.
