I have done quite a bit of searching on the forums and looks like most of the threads are on using E-85, period.

I started thinking about this while driving back from picking up my car in FL and all the 93 octane I was buying always said "may contain up to 10% ethanol"...this was all the way to MO and was posted clearly on the pumps.

Here in NE we only have 91 octane...BUT...E-85 is a little more common. The 91 octane we do have is NOT mixed with ethanol at most pumps (at least...they don't post that it is... ).

Basically, any reason I couldn't find the right formula to get about 93 octane mixing in few gallons of E-85 (105 octane) and STILL only have around 10% ethanol to not overstep the owner's manual recommendation?


The reason I would want to do this is my car has a custom 93 octane tune...meaning Jerry(LET) tuned it...on the dyno...for a couple hours...and I don't really want to erase that with just a generic 91 octane tune. This car made some amazing HP in FL.

The downside of this is that I tried this same idea a few years ago with my stock black SRT-6 (45k miles) and ruined the fuel filter and fuel pump almost immediately..... I think there are multiple reasons why this car would be different, but I still remember getting stuck in Iowa and then shelling out about $700 dollars when all was said and done.



So....verdict?


or

Maybe just stick with more conventional octane boosters when needed like Torco or Klotz?

 

Before anybody chimes in...I guess in order to get 93 octane I would need about 1 gallon of E-85 (105 octane) per 6 gallons of Premium (91 octane) to get 93 octane as an end result. Maybe a tiny more than 10% ethanol....but haven't done the math on that yet.

 

We had 93 octane before they started mixing in the ethanol so it isn't the ethanol that gives us the 93. I'm not sure you are going in the right direction, even though E85 is supposedly higher octane.....it isn't gasoline and I think you will exceed the 10% before you get the octane level you are looking for.

 

Here's a 92 Octane/100 Octane blending chart.

Not sure if it will work for E85 fuel.

7:1 ratio

 

Pretty close though. I guess I could start with a very minor amount and see what I find. I know a few guys are running full E-85 (obviously with a little different tuning) with no problems yet.

I guess the thing I'm more worried about is a repeat of my black SRT-6...but I'm guessing that car had NEVER seen any type of ethanol.

 

I don't know if my plan is for it to be a permanent solution. More like...just until I can get a full custom tune on 91 octane. I know it's not a conventional way to raise octane...just more of a thought.

 

We've had one person (that I know of) convert their XFire to flexfuel capability. Check here for information:

https://www.crossfireforum.org/forum...d-srt-6-a.html

After the conversion, then you should not have any problem adding additional ethanol if that is the route you want to take. Let us know how it works out.

 

Yeah, I read through that entire thread. It looks like he really didn't change out any stock components, just essentially added more fuel as E-85 calls for. I'm just thinking since a lot of places have 10% added in already. If I go 10% ethanol or maybe a little more...(I'm sure 10% is probably very conservative)...should be fine.

Also, I believe bikecop sold his car...so there goes any long term testing..

 

These folks are listed as selling Sonoco 100 Unleaded Fuel at the pump in your area. Motor Fuels - Nebraska Iowa Supply Company Give em' call.

Might be safer then mixing then E85.

Luckily there are 3 stations close by me that pump 100 octane unleaded.

 

the 93 in which your car was tuned on had 10% ethel in it. So adding ethel into 92 wont give you the octane you need. Buy a 1 gallon fuel can with a locking cap or something and load that up with 100+ octane and just mix that in with the 92 and you will be fine.

 

That 100 octane is a little far away (different side of town), but worth it for peace of mind. I'll probably just stick with 91 for daily driving and then raise the octane with some mixing of 100 octane for the track or harder driving. Thanks for the responses, guys.


It's not going to cause any issues using the 93 tune if I drive lightly on 91 octane, right? It's going to get a little expensive fairly quick if I'm constantly running across town and getting a couple gallons of 100 to add to the 91. Maybe I should just get a big 'ole drum of it.



Any experience with Torco or other real octane boosters? Not the "104" junk at Pep Boys.

 

I truely don't think you can achieve what your looking too with E85.
TORCO is the absolute easieat and cheapest way to boost your full tank.

about-----$21.00 per guart (32oz)
24oz. boosts 15 gallons of 91 octane to 95 octane can't beat that!
Generally I pay $9.50 per gallon for 105 octane here in Great Falls.
Our closest TORCO dealer is 175 miles but would like to buy a 5 gallon container this spring.
Mike