E85 Thoughts

[Colinoscopy]

Debating running 3 gallons E85 with 11 gallons 91, this is about E26 total. Would then run the MHD ethanol maps.

-- This might be a stupid question but how do you guys fill up with this ratio if your car is tuned to run a certain amount of E85? For example, say I run my car to empty, then go to a gas station to add 11 gallons of 91, then I have to drive the car home without having added the E85 yet, is this safe? Not trying to store 3 gallons of E85 in my trunk lol.

-- What kind of knock to fuel economy can I expect running ~~ E26? Is it usually worth the power gain?

-- Correct me if I'm wrong, but this is safe to run on a stock car (Aside from FBO)?

Thanks!!

[iminhell1]

blending just sucks.
either go the flex fuel option or full e85. it's just a hassle any other way.

and a low mix, really is no gain to be had that makes the effort worth it.

[Soterios]

Originally Posted by iminhell1

blending just sucks.
either go the flex fuel option or full e85. it's just a hassle any other way.

and a low mix, really is no gain to be had that makes the effort worth it.

Agreed. That low mix will do little to nothing for the car, and just sounds like a pain in the ass.

[bbnks2]

Not sure if these guys have ever ran E85...

The E30 map gives a nice bump in power and consistency. Ethanol burns a bit cooler and you get a few more degrees of timing with the bump in octane and less timing corrections. An E30 mix gives you a solid octane bump from 93aki to 96-97aki.

Use this to calculate how many gallons of E85 you need:http://www.georgebelton.com/E85Calculator.php

I have never had an issue putting in 4gallons of E85 and then topping off with 93. E85 is readily available where I am though so I don't have to go too far out of the way to fill up. The gas tank isn't really empty when you get near E and the fuels are going to mix as soon as you start moving the car as everything in the tank is sloshing around...

[iminhell1]

Originally Posted by bbnks2

Not sure if these guys have ever ran E85...

I'm working on 20 years of almost exclusive use.
And I do tuning, I don't use others tunes.

[bbnks2]

I get it. It can be a hassle. But, with only 91 available he will see some decent gains by blending. With 91aki you can barely run the stock tune let alone add power... I've seen 91aki tunes running negative timing advance.

OP, I would run the 93aki maps maybe? Fuel scalers can account for 3gallons of E85. The E30 self tune isn't that aggressive but I am pretty sue it's designed around 93aki+E85 not 91+E85.

[Zygote55]

Originally Posted by iminhell1

blending just sucks.
either go the flex fuel option or full e85. it's just a hassle any other way.

and a low mix, really is no gain to be had that makes the effort worth it.

This is not correct. I'm in California and run 91ACN maps, but still get timing corrections. When I add just a single gallon of E85 to the tank I get no corrections on the 91ACN maps OR the 91 maps. E85 is really prevalent around me so it's really not hard to just throw a gallon of E85 in and know that I'm not getting any timing corrections...

With 3 gallons of E85 I can run the 93 maps with no corrections, but I don't do that often. It's easier to just always run the 91ACN map so if I don't put any E85 in the tank I'm not worried about it and I don't have to change maps.

[xQx]

Well, I found a huge difference in performance between 98RON and E25 mix.

My fuel economy was terrible whenever I had e85 on the tank; but I think a lot of that was because I drove like a retard a lot more if I had e85 in the tank.

I now run 98RON because I got sick of driving 1/2 an hour out of my way every week to fill the car up.

But to answer your question: Yes, it's totally worth it to run E25. Give it a go and make your own decision. If the service station on our block had E85 on pump I'd be running E50 in my daily driver without question.

Yes, anything up to E30 is 'safe' on a stock car. But you do have to watch your logs. At some point (between E20 and E40) your LPFP isn't going to keep up, and that can leave you running lean, which can quickly end up in a blown up motor.

So - yes it's safe - but only as long as you're being careful.

If you can borrow someone's JB4 (or get one really cheap), it's worth its weight in gold when you're playing with E85. It'll proactively tell you (indicator flash) if your fuel pump crashes or you run lean - rather than relying on reactive reading of logs. Also, if you use the JB4 maps you don't need a specific E85 ratio - it just works with what it's got.

As for driving to and from the station with the wrong map compared to your e85 content - generally speaking you'll be right - just take it easy home from the station (no high revs, no high torque). Lots of people pull into a bay and do the flash at the station (only takes 2 minutes) ... I once got caught with MHD wanting to do a 45 minute write after a flash failed one time, so I just drive home easy

No matter what you do, it's 'best' to find a flex ratio then stick to it so the car can 'learn' that fuel. It's not 'great' to be running E30 one day, E15 the next, Petrol the day after then E30 later in the week. .... though you do find you'll do a lot of this over the first couple of weeks

[JM98]

You will gain a ton of power even running an e30 OTS tune. It's really not that much of a pain... These cars have alot of room for error on stock turbos and OTS maps. For a year I pumped 3 gallons of 91 octane and the rest e85 on my 135i FBO without issue on the MHD V5 OTS E40 map. Get an analyzer or test kit for peace of mind but honestly people are way conservative on their suggestions. Make sure to monitor and log and just send it.