can you run e85 off the bat?

[xshadowspy]

hey guys I'm get the AA tune coming up next month I was wondering about running e85 I heard AA has it just have to ask. But was wondering has anyone else ran e85 did you guys have to upgrade anything or just need a tune for it I have the N51 engine by the way if that makes any difference.

[N54Yankee]

You will lose power. Alcohol produces less energy then gasoline. Unless you have very high compression engine and or forced induction with high boost you will be slower and you will also lose mileage per tankful. Lose, lose.

[xshadowspy]

Originally Posted by N54Yankee

You will lose power. Alcohol produces less energy then gasoline. Unless you have very high compression engine and or forced induction with high boost you will be slower and you will also lose mileage per tankful. Lose, lose.

Ah I see so there would be no benefit for the N51 engine especially because it has lower compression. I've only seen videos of e85 on the N52 they gain about 12whp from it

[N54Yankee]

Originally Posted by xshadowspy

Ah I see so there would be no benefit for the N51 engine especially because it has lower compression. I've only seen videos of e85 on the N52 they gain about 12whp from it

Some people might SAY they get 12 hp on the N52 by simply going E85 but they’re not. Not unless they dramatically raised compression by changing pistons or adding a blower to bump power with e85.
There are better ways to make power with the N51 but not cheap as a simple fuel change. HP usually doesn’t come that easy. Do a search, there are lots of guys here who raised hp, tq nicely on the 51.

[The Wind Breezes]

Originally Posted by N54Yankee

You will lose power. Alcohol produces less energy then gasoline. Unless you have very high compression engine and or forced induction with high boost you will be slower and you will also lose mileage per tankful. Lose, lose.

Well, he may lose power untuned but not for that reason.

Alcohol has oxygen in it so you can stuff MORE of it into the cylinder with a given amount of air than gas. This means you can make a bigger bang, even with the lower amount of energy. Put another way, the difference in air needed to combust is a little greater than the energy difference between gasoline and alcohol. Same with E85.

So, properly mixed and tuned, in a given engine you can make a little more power with alcohol or E85 than gas. It has nothing to do with high compression or forced induction although alcohol / E85 has ADDITIONAL advantages over pump gas in those situations (cooling, detonation resistance).

BUT, if you're looking to go to the trouble of getting E85 and tuning your car for it, you definitely picked the wrong car. N55 135i are not any more expensive to buy than a 128i and the maintenance costs / part failures are the same. And a N55 can turn the power up a LOT over stock, even on pump gas.

[N54Yankee]

https://itstillruns.com/power-differ...-12196474.html

[///Makis]

I agree with pretty much what everyone says but just wanted to add my two cents.

Ethanol is a good solvent, running it every now and again may help clean out your injectors and may help remove carbon build up. Also it will help remove any crud in your tank but at the expense that it will be moving through your engine.

I don't know if anyone has posted a DIY on a gas filter change for the 1 series but If you were to switch to e85 I'd buy two filters and change it first run e85 for a tank or two and change it again.

I believe they blend ethanol with 15 pct gasoline because that's around about the minimum amount of oil you need before the ethanol starts reacting with plastics and rubber. If you were to run straight ethanol or methanol you would definitely have to change your fuel hoses and fuel pump because it can cause the rubber to puff up for certain types of rubber or it can make certain types of plastics very brittle, which of course is less than ideal.

Another problem with running straight ethanol/methanol is there is increased NOx emissions (I believe it's NOx). And because you said you drive an N51 that makes me think you're in a state that has strict emissions control regulation, you may want to not run that fuel before testing. With a tune it may not be the case but I think all things being equal it should lead to increase NOx

If you're looking to add an alcohol, why not consider a methanol injection system. You get some of the benefits of the alcohol but you still get the gas mileage and range of regular gasoline ( you will be paying more total costs though). Also steam from the water/alcohol will increase the knock resistance (not that NA engines have that problem), can help clean the engine, lower the engine temperature, and I recall reading something like water turning to steam increases it's volume by something like 600 times. So you may get a little more umffff from the water, but that may be speculation.


If anyone knows I'm wrong or has information to the contrary, feel free to correct me and tell me I'm an idiot, this is the internet after all