That's on a Mustang dyno too. Known to be heartbreakers.
Convince Me to go e85
- Thread starter CosmicSnail
- Start date
That's on a Mustang dyno too. Known to be heartbreakers.
I'm on the same stage as you sire, I am months away from upgrading my turbo but I contemplating on getting a second map from Freek for that corn love
As a recent E85er here is my input..
Pros
Pros
- your car will evolve into a monster.
- You will look cool as hell when you are pumping E85.
- Your fill ups will be cheaper( but you might be having a lot more fun so you might be filling up more often)
- E85 anxiety (On any road trip wondering if there is E85 in the destination area. this is not a big deal as you can switch back to 93).
- You are limited to gas stations where they sell E85.
- A little less gas mileage. (I get about 10-20 miles less per tank.)
Pretty good summary, but running E28, I get way less mileage than only 10-20 miles less per tank. My average mixed driving MPG goes from ~24 to ~21. I have the EGR disabled, so that 's part of it, but that's a common factor to both tunes. The difference between E28 and 93 is about 15% less MPG, in my experience. I'd say maybe 35-45 miles less per tank.
Thanks for the info guys! Much appreciated 
Not to detract from a gearhead, but I asked Justin (FREEKTUNE) about those specific tuning strategies and he adamantly pointed me away from them. I can't pretend to know all the details, but based on him tuning literally over 1,000 Mazdaspeeds, his opinion goes very far with me.
Also, it's worth mentioning that the information center figure of MPGs has been consistently averaging several MPGs higher than actual when I fill up completely/bust out the calculator to find the exact figure.
Last edited:
Well, I did measurements based off of odometer and pump numbers, and I ran those settings for *years* without issue. When my motor finally let go, it was because I lost 70whp worth of meth during a drag race pull and wound up at 14 AFR and 20 PSI. My piston crowns and valves looked just fine, and the ringland that died did not take the block wall with it.
There are many factors, the most influential of which being your right foot, of course. But chemically speaking (in terms of energy potential of the fuel mix itself), E25-E30 has roughly 15% less energy potential. So everything else being equal, you'd expect that much lower MPG. Problem is, our right feet are hardly consistent in how we drive all the time. Many people don't drive the exact same routes all the time too. And every now and then, a "fast" car needs taught a lesson about Speed 3s being WAAAAY different than regular Mazda 3s, LOL
Anyways, I can tell you I get ~2 MPG less on E28 than on 93. I'm EGR-less too, which lowers mileage, but that's a common factor for both, so therefore moot.
Yes I believe the added power/confidence makes it impossible to drive accordingly. But low mixes Have only a slight effect on MPG. People running E50 will notice the loss a lot moreThere are many factors, the most influential of which being your right foot, of course. But chemically speaking (in terms of energy potential of the fuel mix itself), E25-E30 has roughly 15% less energy potential. So everything else being equal, you'd expect that much lower MPG. Problem is, our right feet are hardly consistent in how we drive all the time. Many people don't drive the exact same routes all the time too. And every now and then, a "fast" car needs taught a lesson about Speed 3s being WAAAAY different than regular Mazda 3s, LOL
Anyways, I can tell you I get ~2 MPG less on E28 than on 93. I'm EGR-less too, which lowers mileage, but that's a common factor for both, so therefore moot.
Since alcohols are more tolerant to detonation, you can also run them leaner. They also generate more power with more timing, requiring less fuel to get there whilst cruising on lean burn tunes. Also, upping the static compression sky high in combination with timing and lean burn can see better than stock MPG even on high blends of ethanol (up to 100%).
I've played with timing and AFR a bit. I actually lost MPG with advanced Timing. leaning out AFR only made the car run like shit. Then again, this was a long time ago when i was pretty newbish
On full corn or relatively heavy mixes, you actually want peak cruise timing in the 40-50 range, not 60. You also don't want to go super stupid on your lean burn, and cap it around the point of diminishing returns which I got at around 15.5:1 AFR (obviously, will likely be different with every car/mix).
Edit:
On my high compression build, I'm going to use a stage 1 OTS map and cut the entire timing table in half, and it may still be too high.
Edit:
On my high compression build, I'm going to use a stage 1 OTS map and cut the entire timing table in half, and it may still be too high.
I've notice there is a few stations with e85 fairly close to me and I am considering going 50/50, but my concern is the inconsistent levels of alcohol in the fuel during the winter months and I just don't think i have the time and patience to teach my partner about how to mix and why to.
Last edited:
ethanol is very consistent. and e25-e30 is perfect
Ethanol ranges between 70-79% actual content (in E85) throughout the year, depending on region, and on season. If you do the math and have the car tuned assuming a ~74.5% amount (or a ~84.5% amount, if the 93 you mix with contains 10% ethanol), your LTFTs will very easily have enough headroom to deal with ethanol concentration variations throughout the year. Another thing you can do is to always get your E85 from the same place, if possible. This minimizes variations.
I have literally hundreds of logs that show this method is sufficient to keep my LTFTs in a great range year-round.
Indeed. Fortunately, I've never had that happen a single time, even running as low as E28. Heck, when I mixed 50/50, I did so with 87. I had so much ethanol in the tank (was about ~40%/volume) that I was able to pull this off and still have zero knock at 20 degrees timing. I didn't push it past that point because I wasn't on rollers.