E85 Octane Rating
05-07-2013, 07:19 PM
#1
E85 Octane Rating I have a local distributor for VP fuel. I was picking up some M1 and he asked me what fuel I planned on running on my Boosted combo.
When I told him E85 he almost **** a brick. He said that the ethanol swing can be from 90% down to 70% depending on the batch, which I was already aware of.
However, he also stated that you were never sure what the octane rating was with it, and that that could hurt the motor.
He owns a prestigious local race shop, and obviously deal with alot of fuel, and engine dyno tuning. Can anyone shed more light on this? I may re post this in the PCM section.
I have to make a fuel decision soon. My car is a street/strip weekend warrior and I would love it if my fuel was not $10+ a gallon. It will be on the dyno next month.
When I told him E85 he almost **** a brick. He said that the ethanol swing can be from 90% down to 70% depending on the batch, which I was already aware of.
However, he also stated that you were never sure what the octane rating was with it, and that that could hurt the motor.
He owns a prestigious local race shop, and obviously deal with alot of fuel, and engine dyno tuning. Can anyone shed more light on this? I may re post this in the PCM section.
I have to make a fuel decision soon. My car is a street/strip weekend warrior and I would love it if my fuel was not $10+ a gallon. It will be on the dyno next month.
05-07-2013, 11:02 PM
#2
You can buy a tester that will tell you the ethanol content. E85 is ~108 octane.
The E85 regulation is a minimum of 51% ethanol I believe. There are different ways of making a at home tester for cheap.
The E85 regulation is a minimum of 51% ethanol I believe. There are different ways of making a at home tester for cheap.
Last edited by Exidous; 05-07-2013 at 11:13 PM.
05-07-2013, 11:17 PM
#3
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Quick Fuel sells a tester. It's just a test tube that you put e85 in fill the rest with water and shake it. As it seperates there is a scale on it that tells you the percentage. Simple,quick and cheap.
05-08-2013, 07:13 AM
#4
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If you have your own supply of E85 then you need to have a tester anyway. No way I am going to stake my engine on a 20% swing. We have always tested all of the E85 in the drum to make sure it is up to par before pumping out of the drum into a car.
We have even been toying with the idea of getting a drum of E98 and cutting it to ensure that it is 100% what we want.
We have even been toying with the idea of getting a drum of E98 and cutting it to ensure that it is 100% what we want.
05-08-2013, 08:19 AM
#5
There are plenty of guys that don't worry about it and have had no issues, me being one of them. My car seems to run the same on the "winter blend" as it does on the "summer blend". I have a junkyard motor in mine though, and am guessing your build has a little more in it, ha.
05-08-2013, 06:51 PM
#8
oh i know your cars quick, but I just wanted future thread viewers to know we meant serious power. The NA guys really would not benefit from what I can tell. I mean I would be happy to test the fuel, but if I data log, cant I just go in and adjust AFR and timing to suit, or do I test the fuel first then change those things. I am just trying to find out if I will constantly be changing things in anticipation of the swing. I certainly dont mind keeping an eye on things.
05-08-2013, 10:57 PM
#9
To be as safe as possible you would need to test the fuel then adjust the AFR accordingly EVERYTIME the ethanol content changed from the last tank.
OR you can run it rich and go conservative on the timing and not worry about it as much.
For peak power and safety you'd HAVE to do the first.
OR you can run it rich and go conservative on the timing and not worry about it as much.
For peak power and safety you'd HAVE to do the first.
05-10-2013, 01:45 PM
#10
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Too much misinformation in here. You will not notice a difference in timing between winter and summer blends. AFR might change slightly but not enough to blow your motor.
Just run it and don't look back. My car has been on e85 for years in Idaho. We have 0 degree winters and 110 degree summers here. Only problem I have ever had is starting under 30 degrees here.
Just run it and don't look back. My car has been on e85 for years in Idaho. We have 0 degree winters and 110 degree summers here. Only problem I have ever had is starting under 30 degrees here.
