# E15 or E30 gas with BNR tune



## DSkidds92 (Oct 30, 2018)

So I recently received my 87 tune from BNR for winter only and premium tune for summer but Ive been using E15 for a month at $1.75/gallon vs $1.82 for regular and $2.65 for premium. I average 34mpg on E15 and 38 on premium. My question is this, could I possibly rum E15 while using the premium (base tune from BNR) or stick with the 87 and use E15?

Our cars are capable of running E15 but nothing more. So anything more would require bigger injectors, fuel pump and possibly lines?

Again this is just a question, I already emailed BNR regarding the matter and while I wait I wanted input on the matter.


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## Barry Allen (Apr 18, 2018)

E15 is a product that is usually 88 octane. The refineries can blend petroleum gasoline to slightly lower octane than the minimum 87 and know that the 15% ethanol will bring it up a few points. They even do that with 87 octane: blending lower octane petroleum with 10% ethanol to achieve 87 octane.

Of course, the labels on the pump are merely the minimum promised. The octane rating could be higher than posted, but the law requires a label with a minimum rating.


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## Taxman (Aug 10, 2017)

If you use lower octane with a high octane BNR tune, it'll drop down to a lower octane profile when it starts pinging. 
All the 87 tune does is force it to start out on the 87 octane profile to eliminate the early pinging. 

It might be interesting to put in 3-4 gallons of E85 and see if it complains. My Saturn runs about -8 to -10 fuel trim on E10, and I can run about E50 without the CEL coming on. E60 gives me a 'fuel trim out of range' code, IIRC it comes on when long term fuel trim gets over +25. I haven't gone over E10 in a Cruze.


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## Barry Allen (Apr 18, 2018)

Taxman said:


> It might be interesting to put in 3-4 gallons of E85 and see if it complains. My Saturn runs about -8 to -10 fuel trim on E10, and I can run about E50 without the CEL coming on. E60 gives me a 'fuel trim out of range' code, IIRC it comes on when long term fuel trim gets over +25. I haven't gone over E10 in a Cruze.


A fuel station near me has pumps where you can get E10, E15, E30, E50, or E85. My Hyundai Accent (with 11:1 compression!) used to run E30 without a CEL, and fuel economy only declined by about 3-4% on average. It was about 15% cheaper per gallon, so it saved money.


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