How to properly Mix e30?

[f93_gc]

So i’ve went ahead and got the E30 Stage 2 tune from BM3 now i’m just waiting for my tank to go to “—“ so i can go ahead and fill my tank. I’ve done the calculations and my first fill should be around 4.3 Gallons E85 and the rest which is like 11.5 of 91. After my first fill up, let’s say i’m at 1/4 tank. How do i calculate how much e85 and 91 to put? I was thinking maybe the only safe and quickest option will always to fill up on completely empty.

[HyeM3]

If you have an iPhone download E85Cal from the App Store. You can put in the percentage of fuel you have left and the target ethanol percentage you want and it'll tell you exactly how much gas and ethanol to put in

[tomlong]

I would not recommend waiting until empty to fill up every time especially if you've already spent the time & effort testing the quality of your pump ethanol around local gas stations and already know exactly which gas stations have the consistent fuel quality you want.

I also try to not wait more than 1/2 empty to fill up, especially if I'm running a e30-e50 tune. My rationale: a quick random encounter in "Mexico" may consume 1/4 of your tank or even more at any given point in time. It would suck for me should the perfect encounter manifests itself but my fuel reserve light just came on. Again, that's just me

I carry 10 gallons of tested e85 in two of these 5 gallon VP Racing jugs with me at all times & keep it simple when fueling up. I generally use the following ratio: 1/3 to 2/5 of e85 + 2/3 to 3/5 of pump gas, effectively aim for 33-40% e85 content in each fill up regardless if it's a full tank or just less than half empty.

The VP Racing jugs have gallon markings on the other side (see pic) that help me know how much e85 I'm pouring in and I utilize the bright gas station lighting along with my finger (line up against line markings) to approximate how much e85 I'm pouring in. For 1/2 gallon pours I best approximate the middle point between each gallon line indicator marking if you want to be super exact. I would also recommend a funnel too ... much less messy. Pretty simple stuff. I pour the ethanol first followed by pump gas, the "click" from the pump gas handle indicating its close to full and corresponding quantity pumped helps me verify my math is correct.

Speaking of math, if the f80 tank is 15.8 gallons according to google, I subtract 1 gallon (my fuel reserve approximate) to get to an effective 14.8 gallons then divide this by 6, which is the total number of dash marks on the fuel gauge, within the F8x instrument cluster. Simple arithmetic gets me to 2.46 or ~2.5 gallons per dash mark.

So for example, if I stopped to fill up with the needle pointing exactly at 2 marks away from full, which is a little more past half full, then I would expect to fill up for 2 x 2.5 gallons = ~ 5 gallons. So I would pour in 2 gallons e85 from my jug followed by 3 gallons of pump gas. Which I know comes out more towards e40 but it allows me the simplicity to plan each subsequent fill ups. My tune also allows me to run mixtures anywhere between e30-e40.

I'm 15k miles into blending this way and going strong. Of course, nothing compares to a flex fuel sensor but I think the manual blending is a disclipined approach, because it really forces you to remain keenly aware of staying in a target range. Plus ECU calibrations that accompany a very wide range of ethanol content I can't imagine be 100% accurately scaled across the tune nor is always ideal for the car. Obviously I'm no expert nor a trained performance automotive professional, so there is liability disclaimer 😀

[TacoJova]

Originally Posted by f82_boi

So i’ve went ahead and got the E30 Stage 2 tune from BM3 now i’m just waiting for my tank to go to “—“ so i can go ahead and fill my tank. I’ve done the calculations and my first fill should be around 4.3 Gallons E85 and the rest which is like 11.5 of 91. After my first fill up, let’s say i’m at 1/4 tank. How do i calculate how much e85 and 91 to put? I was thinking maybe the only safe and quickest option will always to fill up on completely empty.

Considering our cars don't have an actual fuel filter I don't really think it'll be good to run it all the way down all the time. Best way to get it perfect would probably be to just get 5 gallon jugs and mix it i those

[fiveohwblow]

It’s truly not a complex rocket science. Any tune worth its cost will have enough variance built in. I ran e30 for 2 years zero issues just did quick maths at the pump in my head. Don’t overthink it.

[tanzm4_]

For the past year or so I bring it down to <20 miles and fill up 6 gallons of E85 and the rest 91 and I have had no problems. If I need to fill up before E I use the calculator above and estimate you should be ok.

[mdma-zn]

Originally Posted by fiveohwblow

It’s truly not a complex rocket science. Any tune worth its cost will have enough variance built in. I ran e30 for 2 years zero issues just did quick maths at the pump in my head. Don’t overthink it.

Well said!
E30 tunes can handle a lot higher E composition on S55 cars. Log your STFT's and see for yourself...
From a performance perspective try and run higher E comps.

[TopJimmy]

4gal E85 + 10gal Gas = E31 (31.43%)
4gal E80 + 10gal Gas = E30 (30.00%)
4gal E75 + 10gal Gas = E28 (28.58%)

All work fine for an E30 tune, either mixed from quality E85 down to crappy winter E75.

I bring 4gal of E85 in a SureCan quick fill tank and drop it in before filling up with 93.

If you only want a half or a quarter tank to stay light just mix 2-to-5gal or 1-to-2.5gal.

[E92inSG]

Originally Posted by tomlong

I would not recommend waiting until empty to fill up every time especially if you've already spent the time & effort testing the quality of your pump ethanol around local gas stations and already know exactly which gas stations have the consistent fuel quality you want.

I also try to not wait more than 1/2 empty to fill up, especially if I'm running a e30-e50 tune. My rationale: a quick random encounter in "Mexico" may consume 1/4 of your tank or even more at any given point in time. It would suck for me should the perfect encounter manifests itself but my fuel reserve light just came on. Again, that's just me

I carry 10 gallons of tested e85 in two of these 5 gallon VP Racing jugs with me at all times & keep it simple when fueling up. I generally use the following ratio: 1/3 to 2/5 of e85 + 2/3 to 3/5 of pump gas, effectively aim for 33-40% e85 content in each fill up regardless if it's a full tank or just less than half empty.

The VP Racing jugs have gallon markings on the other side (see pic) that help me know how much e85 I'm pouring in and I utilize the bright gas station lighting along with my finger (line up against line markings) to approximate how much e85 I'm pouring in. For 1/2 gallon pours I best approximate the middle point between each gallon line indicator marking if you want to be super exact. I would also recommend a funnel too ... much less messy. Pretty simple stuff. I pour the ethanol first followed by pump gas, the "click" from the pump gas handle indicating its close to full and corresponding quantity pumped helps me verify my math is correct.

Speaking of math, if the f80 tank is 15.8 gallons according to google, I subtract 1 gallon (my fuel reserve approximate) to get to an effective 14.8 gallons then divide this by 6, which is the total number of dash marks on the fuel gauge, within the F8x instrument cluster. Simple arithmetic gets me to 2.46 or ~2.5 gallons per dash mark.

So for example, if I stopped to fill up with the needle pointing exactly at 2 marks away from full, which is a little more past half full, then I would expect to fill up for 2 x 2.5 gallons = ~ 5 gallons. So I would pour in 2 gallons e85 from my jug followed by 3 gallons of pump gas. Which I know comes out more towards e40 but it allows me the simplicity to plan each subsequent fill ups. My tune also allows me to run mixtures anywhere between e30-e40.

I'm 15k miles into blending this way and going strong. Of course, nothing compares to a flex fuel sensor but I think the manual blending is a disclipined approach, because it really forces you to remain keenly aware of staying in a target range. Plus ECU calibrations that accompany a very wide range of ethanol content I can't imagine be 100% accurately scaled across the tune nor is always ideal for the car. Obviously I'm no expert nor a trained performance automotive professional, so there is liability disclaimer 😀

Why so complicated? Aren’t you on Ecutek?

[tomlong]

Originally Posted by E92inSG

Why so complicated? Aren't you on Ecutek?

How is the information I presented complicated? It's elementary school math.

And yes, I'm on Ecutek. Doesn't mean I just dump an unknown quantity of e85 into my tank.

[E92inSG]

Originally Posted by tomlong

How is the information I presented complicated? It's elementary school math.

And yes, I'm on Ecutek. Doesn't mean I just dump an unknown quantity of e85 into my tank.

I apologise if I came across wrongly I didn’t mean that. But doesn’t Ecutek have flex fuel capabilities? That’s one of the big benefits, not having to bother with exact percentages.

[tomlong]

Originally Posted by E92inSG

I apologise if I came across wrongly I didn't mean that. But doesn't Ecutek have flex fuel capabilities? That's one of the big benefits, not having to bother with exact percentages.

Yes, but if you're running say an e60 tune and while filling up you become distracted and say put in enough e85 to make for an e30 blend. While it might be "true" flex fuel integration can account for it, would I trust it if I'm at a 1/2 mile event and about to go up again a twin turbo V10 R8? Do you know if your tuner has written and program the fuel maps in a way to be truly 100% scaled across all ethanol levels across all X number of maps you have capabilities to switch to on the fly, doing so across all varying loads?

Yes, the car will drive just fine under normal part-throttle operation, whether it's e10 (pump gas) or e98 (race trim) but would you go racing your S55 fully knowing or not knowing how much ethanol you pumped or didn't pump into the tank? I don't care if the ecu & flex fuel integration can account or not account for changes in ethanol content, here "common sense" prevails.

And just to be clear, the sensor measures 1-X so it's measuring what is not ethanol. Doesn't account for quality and while you can put a fuel filter in the car, shitty fuel whether it's dirty or not is still shitty fuel. And if you're gonna take the time to test the ethanol for quality, why wouldn't you just make that little tiny extra incremental effort to measure out how much in terms of proportion you want to put in the tank?

People have been blending before flex fuel sensors were invented, and will continue to do so.

[E92inSG]

Wow nice. Thanks for the info. Very informative and it’s clear you are very clear and calculated in your approach to modifying your vehicle. 👍

Personally I am in the opinion of trusting my tuner and ecutek with regards to scaling of fueling and ignition timing/ boost etc according to E%

We don’t have E85 locally so I just dump whatever amount of pure ethanol I feel like on that day into my tank and run anywhere from E10-E40 as displayed in my ecutek app with Bend Calibration’s flex fuel kit & sensor. I log all my 100-200 runs pretty religiously and on average do twice a week as I’m still working on the tune.

In any case, I don’t want to go off topic anymore in this thread.

Hope OP finds a good reliable way to get his blending question answered! 👌

[tomlong]

Originally Posted by E92inSG

Wow nice. Thanks for the info. Very informative and it's clear you are very clear and calculated in your approach to modifying your vehicle. 👍

Personally I am in the opinion of trusting my tuner and ecutek with regards to scaling of fueling and ignition timing/ boost etc according to E%

We don't have E85 locally so I just dump whatever amount of pure ethanol I feel like on that day into my tank and run anywhere from E10-E40 as displayed in my ecutek app with Bend Calibration's flex fuel kit & sensor. I log all my 100-200 runs pretty religiously and on average do twice a week as I'm still working on the tune.

In any case, I don't want to go off topic anymore in this thread.

Hope OP finds a good reliable way to get his blending question answered! 👌

All good brotha. I love the real-time dash board on Ecutek, let's me see what each of the 6 cylinders are doing. Like anything, I just try to do what makes sense for me. I'm not the smartest guy out there so I sometimes do what I feel comfortable with.

Maybe you can buy some ethanol online and see if they ship international 😂 ... it's like crack cocaine and highly addicting here.

[TopJimmy]

For those of you who like to calculate mixed fuels here's a tool I've created. If you follow the link a read-only copy will open, which you can download (it will make an unlocked copy of) the XLSX file. I suggest that you upload this to your Google Sheets so it's available on your phone. I formatted it to fit easily on a small screen, so pinch to zoom.

Directions are listed... Basically fill in values for what's in-tank and what you plan to add, and the output gives accurate calculations of Ethanol content. I have columns for in-tank fuel, pump gas, E85 pump, and also race alcohol. The output even gives details of your mixed gasoline content, to help with additives.

https://docs.google.com/spreadsheets...it?usp=sharing

[papasmurf_m3]

Originally Posted by HyeM3

If you have an iPhone download E85Cal from the App Store. You can put in the percentage of fuel you have left and the target ethanol percentage you want and it'll tell you exactly how much gas and ethanol to put in

Thank you for this!

Ive been running flex fuel but, sometimes if I want to run a certain mixture like E50 and currently on E79 I can easily blend down to exactly what I want.

[TopJimmy]

Happy to help out my brothers and sisters.

[SE7EN335]

If you are using BM3 E30 map, just dump in half E85 half 93 oct/98 Ron every time you fill up. It usually equates to around a E40 mix and its always good to have a positive safety buffer over the required ethanol mix when running the E30 tune

[TopJimmy]

Good 85% mixed 50/50 is E47.
Winter 75% mixed 50/50 is E42.

I'm a lab rat...prefer to test and mix quality fuels within 2% of my target for my custom "kill tune". OTS and mild custom tunes have a little wiggle room for octane and ethanol mix, but a custom kill tune does not.

[AND1_M3]

So what the most WHP you can get on 93/91 fuel? Do you get way more out of running E85? Just asking cause I am debating on going E85

[MisterF80M3]

Originally Posted by AND1

So what the most WHP you can get on 93/91 fuel? Do you get way more out of running E85? Just asking cause I am debating on going E85

~500WHP on stage 2 FBO 91

~600WHP on custom tune E85

[AND1_M3]

Originally Posted by MisterF80M3

~500WHP on stage 2 FBO 91

~600WHP on custom tune E85

Guess E 85 is the way to go, did you have to get anything else to go on custom e85 tune? Like PI, Upgraded fuel pump?