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Sooooo....normally these cars run really rich from the factory at WOT, and I'd heard of people saying they picked up with E30 but holy crap! Wish someone told me about this 2 years ago when I first got mine tuned. Went from 85mph in the 1/8th (stock, 380rwhp) to 89mph on an OE Tuning 91 tune, and the SAME TUNE on E30 trapped 92mph and picked up another 50rwhp! Running 3mph faster in the 1/8th is also in line with the power increase on the datalogger (old Gtech) I was using. Never expected the car to pick up that much......
this has piqued my interest and I am absolutely clueless about Ethanol. What hardware is needed to run ethanol for our vehicles?
Apparently, nothing really, up to about E50....just a tune. Or in my case not even that. I'm leaving some HP on the table for sure, but I'm fine with that. I'm probably only going to run E30 when I go to the track or if I have to race a buddy or something I know e85 is hard on fuel pumps, injectors, tanks, and catalytic converters, but 85% ethanol is a lot different that 30%. Shoot most CA fuel has up to 10% anyways. At this point I've beat on the car so much I'm willing to try E30 at least and "see what happens." My only worry is running too lean, part of the reason I'm only running 1/8th mile, cause I don't know my AFR.
As said bout to e47-e50 the fuel pumps can handle the load - it takes more (more volume) e-mix to produce power than on 91-93 octane fuel so the fuel pumps have to compensate.
also re: ethanol drying out seals - there's enough protection from the 93 octane to rule this issue out, and the e85 won't hurt your cats
i don't use in line fuel sensor - I use an app "e85 mix"
Last edited by PeterUbers; Nov 6, 2025 at 03:41 PM.
yeah also 100 octane fuel is hard to find in my area as well!
I'd try it next time you're at like 1/4 tank just throw a gallon of e85 in, drive around for a few miles to let it mix in, then get on it a few times. I'll be curious to see if you'd have a similar result. I know I could feel the difference in mine seat-of-the-pants.....
As said bout to e47-e50 the fuel pumps can handle the load - it takes more (more volume) e-mix to produce power than on 91-93 octane fuel so the fuel pumps have to compensate.
also re: ethanol drying out seals - there's enough protection from the 93 octane to rule this issue out, and the e85 won't hurt your cats
i don't use in line fuel sensor - I use an app "e85 mix"
Thats bad ***! I've been wanting to retune @ Dyno-Comp in Scottsdale, AZ. They do all high end cars. So we can run an E40 mix with out any real issues??? We only have 91 octane here all over or E85 pumps. Tom's Thumb is where all super cars and hyper cars go in Scottsdale. They have 95 octane and 100 at the pump. Was thinking of getting some 95 but the MBH tune I have is for I believe 91.
Thats bad ***! I've been wanting to retune @ Dyno-Comp in Scottsdale, AZ. They do all high end cars. So we can run an E40 mix with out any real issues??? We only have 91 octane here all over or E85 pumps. Tom's Thumb is where all super cars and hyper cars go in Scottsdale. They have 95 octane and 100 at the pump. Was thinking of getting some 95 but the MBH tune I have is for I believe 91.
A few different companies do "E47" tunes, which makes mixing easy, it's just half and half pretty much. I think after that you need to upgrade the fuel system.
A few different companies do "E47" tunes, which makes mixing easy, it's just half and half pretty much. I think after that you need to upgrade the fuel system.
Hmmm, ok Ill have to look into this and talk with the tuner. As hot as it gets here in the summer ethanol would be so nice. Im also getting the bigger AIT cooler radiator with the higher flow pump upgrade before summer.
A few different companies do "E47" tunes, which makes mixing easy, it's just half and half pretty much. I think after that you need to upgrade the fuel system.
Hmmm, ok Ill have to look into this and talk with the tuner. As hot as it gets here in the summer ethanol would be so nice. Im also getting the bigger AIT cooler radiator with the higher flow pump upgrade before summer.
I'd try it next time you're at like 1/4 tank just throw a gallon of e85 in, drive around for a few miles to let it mix in, then get on it a few times. I'll be curious to see if you'd have a similar result. I know I could feel the difference in mine seat-of-the-pants.....
I'm around a 1/3 tank right now, may just give it a shot today when I leave the house if time permits.
I got down to 64 miles and added 1 gallon of E85 tested at E88. This Chevron is were i
I see high HP M4s and other turbo cars go. They said its consistent in the higher ethanol content. Then put in 12.24 gals of 91. Im not sure I tried to use the calculator but I'm all over the place with what level im at. Just trying for a E20 mix on my MBH tune. Any body that can help thanks! The throttle response seems to be better. Haven't beat on her just experimenting.
I got down to 64 miles and added 1 gallon of E85 tested at E88. This Chevron is were i
I see high HP M4s and other turbo cars go. They said its consistent in the higher ethanol content. Then put in 12.24 gals of 91. Im not sure I tried to use the calculator but I'm all over the place with what level im at. Just trying for a E20 mix on my MBH tune. Any body that can help thanks! The throttle response seems to be better. Haven't beat on her just experimenting.
You have a Dragy or anything to test it? Be interesting to get some empirical results.....I went from 89mph in the 1/8th mile to 92mph.....I know it might not seem like much but on a car that heavy it really is. Is yours tuned or stock? I now Eurocharged and RSPDMV and others do dedicated E50 tunes, but they're around $1500 I think. Plus I'd wonder about long term effects on cats if you still run them.
You have a Dragy or anything to test it? Be interesting to get some empirical results.....I went from 89mph in the 1/8th mile to 92mph.....I know it might not seem like much but on a car that heavy it really is. Is yours tuned or stock? I now Eurocharged and RSPDMV and others do dedicated E50 tunes, but they're around $1500 I think. Plus I'd wonder about long term effects on cats if you still run them.
I dont have a way to test whats in the car now just a ethanol tester bottle. I want to get a ethanol sensor if I do go higher like E40 to see the real time ethanol content. I just think fuel pump and gaskets will dry out and become a problem so not 100% sure if I want to run that risk. Unless Dyno-Comp says otherwise. $1300 for ECU and TCU retune is what I was told. I have a MBH tune right now for my M157 motor swapped 2014, full 3" catless downpipes with H pipe. I'll get pictures tomorrow and put in the thread on here.
3 mph is good for who knows what ethanol content you where running at the time. As you said our cars are not light. I need to run mine at the track just to gage what it's doing compared to a custom tune with or without E85 variation.
Last edited by Desert_benz; Dec 12, 2025 at 01:18 AM.
I dont have a way to test whats in the car now just a ethanol tester bottle. I want to get a ethanol sensor if I do go higher like E40 to see the real time ethanol content. I just think fuel pump and gaskets will dry out and become a problem so not 100% sure if I want to run that risk. Unless Dyno-Comp says otherwise. $1300 for ECU and TCU retune is what I was told. I have a MBH tune right now for my M157 motor swapped 2014, full 3" catless downpipes with H pipe. I'll get pictures tomorrow and put in the thread on here.
3 mph is good for who knows what ethanol content you where running at the time. As you said our cars are not light. I need to run mine at the track just to gage what it's doing compared to a custom tune with or without E85 variation.
Only problems with pumps and lines I've seen on newer cars are running full E85.....usually E40 or E50 they're fine if they're tuned for it, and if not, I like E20-E30 is still OK. What's funny is that there is literally one single E85 station in our whole city, and it's usually very consistent at 70-80 percent. I just mixed for E30 and figured it ran what it ran. It's rainy and foggy out right now but I got a Dragy and I'm going to try at least one 60-130 to see how that compares. Best my car is gone in the quarter is a 12.50, 12.54, and 12.63, although I've went as slow as 13.0 in hot weather with a bad DA. These cars LOVE cold weather. Anyways, there's my story LOL. Hopefully I'll get more data soon.
Only problems with pumps and lines I've seen on newer cars are running full E85.....usually E40 or E50 they're fine if they're tuned for it, and if not, I like E20-E30 is still OK. What's funny is that there is literally one single E85 station in our whole city, and it's usually very consistent at 70-80 percent. I just mixed for E30 and figured it ran what it ran. It's rainy and foggy out right now but I got a Dragy and I'm going to try at least one 60-130 to see how that compares. Best my car is gone in the quarter is a 12.50, 12.54, and 12.63, although I've went as slow as 13.0 in hot weather with a bad DA. These cars LOVE cold weather. Anyways, there's my story LOL. Hopefully I'll get more data soon.
That's good times and I want to get one of those devices you have that looks awesome. Im not tuned at all for anything more than pump gas so I probably shouldn't be mixing in over 10% ethanol now. Im calculated around 20% and I don't think I feel anything more than a bit more throttle response. Where did you get your device from?
I finally experimented yesterday and there was definitely noticeable improvement on the butt dyno. the car felt like it ran smoother and quieter overall and definitely more responsive. I just added 1.25gal to a little under half a tank of 91.
I braved a E30 mix on my tune and its not having it. I figured out that calculator and my car just feels not right. Im guessing running to lean now, so I have to baby it till I run more gas out. I went to aggressive for my tune im sure. I better leave well enough alone. Glad you guys are getting good results. Now to really get a dyno tune, not a dyno tune flashed to my ECU.
I braved a E30 mix on my tune and its not having it. I figured out that calculator and my car just feels not right. Im guessing running to lean now, so I have to baby it till I run more gas out. I went to aggressive for my tune im sure. I better leave well enough alone. Glad you guys are getting good results. Now to really get a dyno tune, not a dyno tune flashed to my ECU.
I think with the engine swap and custom tune you're just going to have to get it tuned for E30. Sorry it wasn't a simple "fill and go faster" for ya LOL.
Soooo, got some confirmation last night that I'm not crazy!! Haha. Most of the time I trap 111mph during quarter passes, but I did trap 112mph once in hero DA. This time I was in hero DA again, but now I was on E25 and, 115mph! woohoo! I had to pedal it until middle of 3rd too thanks to less than awesome roads, but picking up 3-4mph of trap in the quarter is definitely showing a good bump in horsepower. Calculators right now put the car at about 470rwhp! I'm going to dilute the fuel back down to about E15, but I'm more than happy with the results. Car is on an OE Tuning 91 Octane tune, and is completely stock, including downpipes and air filters.
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I know e85 is hard on fuel pumps, injectors, tanks, and catalytic converters, but 85% ethanol is a lot different that 30%. Shoot most CA fuel has up to 10% anyways. At this point I've beat on the car so much I'm willing to try E30 at least and "see what happens." My only worry is running too lean, part of the reason I'm only running 1/8th mile, cause I don't know my AFR.
