E85 and 87 Octane?

[rudypoochris]

Anyone doing this? I run 91 now with E85, but figure if I can hit my octane targets with 87/e85 why not save the cash? I know 87 can be up to 15% ethanol already. Does the same hold true for 91? My main concern is trim out. Is anyone else doing this?

[benzy89]

Not worth it to save some money, especially cause you prob won't (ethanol reduces your MPG, more E85 = less MPG = more money spent at the pump). You're ethanol:gasoline ratio is gonna be much higher, so (like you acknowledged) you're more likely to max your trims & overwork your HPFP

[Legionofboom]

OP, I see what you did their, but that $#@!s weak

just run 93/E85. You do drive a BMW

[Eric335]

OP, I see what you did their, but that $#@!s weak

just run 93/E85. You do drive a BMW

Have you been running any E85? I cant find any in the Naples area, the closest is like Ft.Myers?

[rudypoochris]

So 91 octane is pure gas and no ethanol? I am not being cheap, I am being realistic. If I see no benefit in knock suppression with 91 over 87, why bother with 91? I didn't earn enough money to buy a BMW by being stupid enough to waste it.

Not worth it to save some money, especially cause you prob won't (ethanol reduces your MPG, more E85 = less MPG = more money spent at the pump).

E85/91 in a 50-50 ratio has lowered my MPG about 1mpg using JB4. I easily save money when using e85, but obviously that isn't the main reason I use it.

[rdeterman]

So 91 octane is pure gas and no ethanol? I am not being cheap, I am being realistic. If I see no benefit in knock suppression with 91 over 87, why bother with 91? I didn't earn enough money to buy a BMW by being stupid enough to waste it. E85/91 in a 50-50 ratio has lowered my MPG about 1mpg using JB4. I easily save money when using e85, but obviously that isn't the main reason I use it.

you only lost 1mpg when blending? i lost about 5 across the board

[rudypoochris]

you only lost 1mpg when blending? i lost about 5 across the board

That sucks. What map? My timing wasn't good on 91 only. I recovered a lot of the mpg simply from having good timing. You can also run the E85 afrs leaner which gets you better economy. Obviously when you floor it and use the full power you will see worse economy. I was talking just steady state going to work and cruising, normal driving. I see 2-3mpg less on average tanks, but that's because I beat the $#@! out of it doing WOT pulls daily. That extra power has to be met with more fuel. Under the same conditions though I see maybe 1mpg less.

[RnmEvo9]

I honestly wouldn't want to risk it just to save a few dollars per tank.

[leo985i]

On jb4 map5 and about 35% to 40%. I actually get better mileage for some reason. I think mileage is affected when higher levels of ethanol are used. Not sure about 87 youth, I'm still using 91 oct, piss water but highest we have down here.

[rudypoochris]

On jb4 map5 and about 35% to 40%. I actually get better mileage for some reason. I think mileage is affected when higher levels of ethanol are used. Not sure about 87 youth, I'm still using 91 oct, piss water but highest we have down here.

Exactly. You need auto tuning to realize it though. Ideal is the 25% range I believe.

I honestly wouldn't want to risk it just to save a few dollars per tank.

I'll do it and log my results. There isn't really any risk tbh. Worst case I autotune boost down to 15psi instead of 18, or I trim out and throw a run lean. I cant test until the new clutch comes unfortunately.

[Legionofboom]

Have you been running any E85? I cant find any in the Naples area, the closest is like Ft.Myers?

The closest is Palm beach BLVD, I live near downtown Ft Myers, so its only 15 minute drive, If you wanna meet up PM me!

[Eric335]

The closest is Palm beach BLVD, I live near downtown Ft Myers, so its only 15 minute drive, If you wanna meet up PM me!

Oh i see. Im thinking of going the meth route simply because of the 30+ minute drive to E85

Do you go to the Friday night meets by Hollywood 20 theater/Moes/Chick fil a/Petco plaza? I saw your car there once. I usually park with the silver 300ZXTT, a white Supra, and a grey EVO (although he drives an R33 now....). You should come out next time i go. Im not sure if ill be going this weekend...

And i think i still have your cell # (maybe), ill double check.

[Legionofboom]

Oh i see. Im thinking of going the meth route simply because of the 30+ minute drive to E85

Do you go to the Friday night meets by Hollywood 20 theater/Moes/Chick fil a/Petco plaza? I saw your car there once. I usually park with the silver 300ZXTT, a white Supra, and a grey EVO (although he drives an R33 now....). You should come out next time i go. Im not sure if ill be going this weekend...

And i think i still have your cell # (maybe), ill double check.

Yeah i go down their from time to time. Im running Meth +E85 right now.

Just go the drum route and leave it in your garage!

If not just pm me ill send it over.

[rdeterman]

That sucks. What map? My timing wasn't good on 91 only. I recovered a lot of the mpg simply from having good timing. You can also run the E85 afrs leaner which gets you better economy. Obviously when you floor it and use the full power you will see worse economy. I was talking just steady state going to work and cruising, normal driving. I see 2-3mpg less on average tanks, but that's because I beat the $#@! out of it doing WOT pulls daily. That extra power has to be met with more fuel. Under the same conditions though I see maybe 1mpg less.

map 5.. i havent taken a road trip to calculate mileage vs 91 only but my in town has dropped on avg 5mpg from 18ish to 13ish.. my driving style hasnt changed that i know of

[Payam@BMS]

Lowering to 87 will still lower the percentage of octane rating. Although you're still getting the 10% ethanol that is in all premium gas. It's still not the same octane rating as you'd think when mixing. I use this calculator and it is bookmarked for me lol. Just go down to where it says "Octane results from blending 2 fuels" and voila.

http://www.intercepteft.com/calc.html

[benzy89]

So 91 octane is pure gas and no ethanol? I am not being cheap, I am being realistic. If I see no benefit in knock suppression with 91 over 87, why bother with 91? I didn't earn enough money to buy a BMW by being stupid enough to waste it. E85/91 in a 50-50 ratio has lowered my MPG about 1mpg using JB4. I easily save money when using e85, but obviously that isn't the main reason I use it.

No, all pump gas can vary between 0-10% of Ethanol content. The problem is to get the octane rating that you're looking for is you'll have to blend in more E85 -- More E85 = lower MPG, more stress on the HPFP & Injectors, and a higher possibility of hitting your fuel trims. My MPG has also suffered a noticeable amount (usually between 30-50 miles less out of a full tank, E85 blend). Also, high ethanol content is known to clog injectors (another short coming on this platform).

My perspective is why bring on additional problems when the fueling system is an achilles heel on this platform?

[rudypoochris]

No, all pump gas can vary between 0-10% of Ethanol content. The problem is to get the octane rating that you're looking for is you'll have to blend in more E85 -- More E85 = lower MPG, more stress on the HPFP & Injectors, and a higher possibility of hitting your fuel trims. My MPG has also suffered a noticeable amount (usually between 30-50 miles less out of a full tank, E85 blend). Also, high ethanol content is known to clog injectors (another short coming on this platform).

My perspective is why bring on additional problems when the fueling system is an achilles heel on this platform?

I can hit 17.5 psi of boost at 40% E85/91. I can run around 55-60% E85/91 before trim issues/codes. I think I can probably hit my octane targets with 50% 87/E85.

I am obviously not concerned with clogging anything. I have been running E85 50% blend for over 35,000 miles. I would think you will get lower MPG without autotuning almost certainly since you can't get the most possible timing out of the tune while being safe.

I was mainly looking to see if anyone has tried this before and if so if there were any real blockers. It appears so far there are not, I will do it and get the results back once my clutch comes in.

[benzy89]

I'm personally done with E85 until I can get my hands on a sensor and/or a tune that specifically adjusts for the varying ethanol concentrations. I'm not a fan of this guessing game & data logging to make sure there are no significant timing corrections, when I already know that E85 is not always 85% ethanol (can legally vary anywhere between 70-85%).

[Terry@BMS]

I'm personally done with E85 until I can get my hands on a sensor and/or a tune that specifically adjusts for the varying ethanol concentrations. I'm not a fan of this guessing game & data logging to make sure there are no significant timing corrections, when I already know that E85 is not always 85% ethanol (can legally vary anywhere between 70-85%).

If you are not using a piggyback that can monitor fuel trims and knock full time why not tune for E60 and then always run 100% E85?

[JStang]

I am working on an E45 map with Jake at PTF and added some E85 yesterday. The stuff is getting expensive at my station. I paid $3.79 per gallon which is higher than 93 .

[benzy89]

If you are not using a piggyback that can monitor fuel trims and knock full time why not tune for E60 and then always run 100% E85?

Like I said, if the tune can't adjust to the specific ethanol content & I'm (basically) guessing, it's far from the smartest way to run a performance setting. I'll stick to pump gas (93) or MS109 if I wanna go fast

[rudypoochris]

I'm personally done with E85 until I can get my hands on a sensor and/or a tune that specifically adjusts for the varying ethanol concentrations. I'm not a fan of this guessing game & data logging to make sure there are no significant timing corrections, when I already know that E85 is not always 85% ethanol (can legally vary anywhere between 70-85%).

It really isn't that complicated. The first time I do a change, I log it. After that it doesn't require attention. I run 50% all the time with no problem. Every once in a while I push it and take a log. The thing autotunes itself... I don't care about timing corrections since the JB4 handles that automatically on Map 5 and I will just see less boost if I am octane limited.

[rudypoochris]

Like I said, if the tune can't adjust to the specific ethanol content & I'm (basically) guessing, it's far from the smartest way to run a performance setting. I'll stick to pump gas (93) or MS109 if I wanna go fast

I don't get it?

You will always be covered with an E60 tune pouring E85 100% in. You aren't leaving much on the table if anything with stock turbos in this scenario since you are already boost capping and will have enough octane to run the most aggressive of timing.

[rooringhusky]

I honestly wouldn't want to risk it just to save a few dollars per tank.

^+1

I even trip out about using 91 versus 93 since most testing is usually done with 93....Wouldnt try to save to money...but best thing to do is log and see what happens if you really do choose to

Besides...your ALREADY savings money using E85

[themyst]

Isn't the "15%" portion of E85 actually 87 octane gasoline? If so, just increase the amount of E85 you put in the tank during the winter months.