An official E9x E85 thread

[RE36TRO]

The subject of running E85 on turbo'd M's are plentiful, ie the F80 forums. However the search function doesn't yield much feedback on running E85 on our E9x platform, specifically NA applications.

I wanted to start a thread (or revive the subject) for our platform in hopes of sharing experiences, challenges/risks, downfalls and benefits running E85.

I've participated in this years group buy for Alex's Alpine tune and opted for the E85 map in addition to 91. Being here in NorCal it's decently available and have had amazing results on my turbo E36, I figure why not.

[bmwm3s65]

I also purchased and am running Alex's e85 tune. I have not dynoed yet, but i think with e85+pulleys+tp+intake+exhaust i make about 410 or more to the wheels. Couple things i noticed are it cranks slightly longer before starting, idles a little rough because of a slightly lower idle and exhaust has little to no soot build up compared to 91 or 93 octane.

[RE36TRO]

Great feedback. Yes i agree, with my E36 especially in the winter it takes a few attempts to crank. Not to mention a nice little smoke screen in the cold weather. I'm running just a dinan intake and ACM modded muffler hoping to hit 400 as well.

[LakeSurfer]

I'm relatively new to the E85 tune subject. With the e85 tune do you run pure e85 or a blend or what? I'm in southern Florida and it's pretty available here as well.

[RE36TRO]

Yes basically straight from the pump. Ideally drain the 91/93 you have as much as possible and fill her up with the corn juice and tune.

[bmwm3s65]

I drive as close to empty as i can. On my car as long as i am about 23 miles or lower until empty on 93 or 91, and switch over to e85 i have no problems. Alex also recommended to switch back to 91 or 93 after running a few tanks of e85 to prevent corrosion issues. i typically run 6 or 7 tanks of e85 then switch back to 93 for a few tanks.

[KawBoy]

I know this is off subject, but I have no E85 tuning, but burn a full tank of E85 from time to time. I love it.

[RE36TRO]

Originally Posted by KawBoy

I know this is off subject, but I have no E85 tuning, but burn a full tank of E85 from time to time. I love it.

Hmm. Didn't know this would benefit. I'd assume little to no gains with the usual mpg reduction?

[tdott]

Having an few issues with my e85 tune.

I do have becker headers so that might be some of it as I had a slight issue on 93 also but it got worse with e85 even thou Alex said he made changes for headers, it bogs/stumbles at low rpm high load. Had the car freak out and go into limp mode a few times even on fresh E85.

Will get my injectors cleaned/flow tested once businesses are back to normal.

Or just switch back to 93. Not sure the benefits are worth it.

[RE36TRO]

Hmm definitely not an expert but I did have a similar issue with a previous vehicle which tuned out to be spark plug/coil related. Hope you get it ironed out.

[KawBoy]

Originally Posted by RE36TRO

Hmm. Didn't know this would benefit. I'd assume little to no gains with the usual mpg reduction?

No, no gains that I can notice. Motor runs fine though. Mileage is pretty bad; it goes down to about 9 mpg from the usual 13 mpg.

[LakeSurfer]

Originally Posted by bmwm3s65

I drive as close to empty as i can. On my car as long as i am about 23 miles or lower until empty on 93 or 91, and switch over to e85 i have no problems. Alex also recommended to switch back to 91 or 93 after running a few tanks of e85 to prevent corrosion issues. i typically run 6 or 7 tanks of e85 then switch back to 93 for a few tanks.

So do you have to "retune" each time you go from 85 to 93? I'm guessing you do this through the OBD2 and a laptop?

[RE36TRO]

Yes. Just reload the proper map (7-8min process).