[Estorilblue340i]

I just filled up 2 gallons of e85 on my completely stock 340i and the rest 91 and wow, huge difference in sound, and feels way more torquey. The pulls are way harder and I am having no problems with the car misfiring.
Try at your own risk, every car is different

[chenry]

Originally Posted by Estorilblue340i

I just filled up 2 gallons of e85 on my completely stock 340i and the rest 91 and wow, huge difference in sound, and feels way more torquey. The pulls are way harder and I am having no problems with the car misfiring.
Try at your own risk, every car is different

How much 91 did you already have in your tank at the time (and/or fill to) - trying to understand the ratio of 91 to E85 you ended up with

[Estorilblue340i]

Originally Posted by chenry

How much 91 did you already have in your tank at the time (and/or fill to) - trying to understand the ratio of 91 to E85 you ended up with

I had 3 quarters a tank of 91

[chenry]

Originally Posted by Estorilblue340i

I had 3 quarters a tank of 91

so roughly 12 gallons of 91 to 2 gallons of E85 / 6:1....I may have to give that a try - thanks!

[Livetodrive]

Putting 2 gal. of E85 into a tank that had 13.5 gal (3/4 full) of E10 gas resulted in 20% ethanol in your tank. Do you realize the internal damage that can occur to a vehicle long-term with that much ethanol if it wasn't designed for it? The ethanol will attack the aluminum and magnesium parts. Hoses may swell. You're not going to notice it immediately, but the engine will be wrecked and the cause will be obvious, voiding the warranty. From a short-term perspective, water in the tank can settle out and clog various parts. Don't do it!

[jgoens]

Originally Posted by Livetodrive

Putting 2 gal. of E85 into a tank that had 13.5 gal (3/4 full) of E10 gas resulted in 20% ethanol in your tank. Do you realize the internal damage that can occur to a vehicle long-term with that much ethanol if it wasn't designed for it? The ethanol will attack the aluminum and magnesium parts. Hoses may swell. You're not going to notice it immediately, but the engine will be wrecked and the cause will be obvious, voiding the warranty. From a short-term perspective, water in the tank can settle out and clog various parts. Don't do it!

I regularly used e40 (about 4.5 gal E85) on my e90 335 and now the same on my f30. Have for years. There are many accounts of people using E85 and I have never seen a permanent damage issue due to moderate E85 usage.

[StockLOL]

Originally Posted by Livetodrive

Putting 2 gal. of E85 into a tank that had 13.5 gal (3/4 full) of E10 gas resulted in 20% ethanol in your tank. Do you realize the internal damage that can occur to a vehicle long-term with that much ethanol if it wasn't designed for it? The ethanol will attack the aluminum and magnesium parts. Hoses may swell. You're not going to notice it immediately, but the engine will be wrecked and the cause will be obvious, voiding the warranty. From a short-term perspective, water in the tank can settle out and clog various parts. Don't do it!

Yea I’m pretty sure it won’t hurt the engine from all that I’ve read but I thought the b58 just didn’t like e85? I was very curious about this as well because past n54 and n55 were much more powerful with e85 mixes. Also many other performance cars get huge jumps in power running ethanol mixes.

[RoundelM3]

Ethanol has only about 73% of the thermal efficiency of gasoline but has a higher octane rating. It just allows a stock engine to develop its full power by raising the octane level of lower-octane fuel and preventing the DME from pulling back boost/fuel/ignition to counter detonation. Ethanol is corrosive to some of the seals and rubber parts in the fuel system and can eventually damage that system if used in large quantities. BMW clearly states that no more than 15% ethanol content should be used in any of its current gasoline engines.

Essentially, ethanol is nothing more than an octane-booster that enables higher states of tune while preventing pre-ignition. It's not rocket fuel.

[Estorilblue340i]

Originally Posted by Livetodrive

Putting 2 gal. of E85 into a tank that had 13.5 gal (3/4 full) of E10 gas resulted in 20% ethanol in your tank. Do you realize the internal damage that can occur to a vehicle long-term with that much ethanol if it wasn't designed for it? The ethanol will attack the aluminum and magnesium parts. Hoses may swell. You're not going to notice it immediately, but the engine will be wrecked and the cause will be obvious, voiding the warranty. From a short-term perspective, water in the tank can settle out and clog various parts. Don't do it!

Originally Posted by Livetodrive

Putting 2 gal. of E85 into a tank that had 13.5 gal (3/4 full) of E10 gas resulted in 20% ethanol in your tank. Do you realize the internal damage that can occur to a vehicle long-term with that much ethanol if it wasn't designed for it? The ethanol will attack the aluminum and magnesium parts. Hoses may swell. You're not going to notice it immediately, but the engine will be wrecked and the cause will be obvious, voiding the warranty. From a short-term perspective, water in the tank can settle out and clog various parts. Don't do it!

It's a lease, fuck it

[Mouse]

Originally Posted by Estorilblue340i

It's a lease, fuck it

[328iX]

Ethanol is also less energy dense, meaning you need more fuel to make the same power. Your injectors aren't calibrated for this, so effectively you're running your car lean.

[Brett530]

My average MPG dropped by 2 MPG with 2 gal of E85 to a full tank of 91.
Yes, less energy dense.