[Nezil]

Originally Posted by cookiesowns

You can do this on the OTS Stage 1.

Add about .5 gallons to basically a very near full tank of 91. Monitor your STFT as you drive. Once the STFT's start varying more than 10% the ethanol is beggining to blend and do some logs then. If the trims go over +-30% ( .3 on BM3 ) You might have to run the E30 map for a bit until you burn your fuel over. I'd say start with .2gallons to start on 10gallons.

Thanks for this advice. As I said, I do have 6 gallons of E85 waiting at home so I'll try this as soon as I'm back. I'm in Texas for a couple of days for work (great gas, at low prices, but no car here!), and will be able to start this testing on Wednesday I'd have thought.

Originally Posted by SeanWRT

Every tune take advantage of octane margin left by stock tune, to some degree. As you don't have much of it and apparently have to increase octane for the tune, which in my opinion only make sense for drag racing or track event. I would suggest you stop trying to mix up fuel which can have inconsistent octane, to find the answer you already know.

I absolutely agree with you that mixing large quantities of gas is going to be a waste of time and effort. It's unsustainable as well because it's a real pain to keep Race gas at home and remember to add some before filling up, and totally impossible if travelling.

Having said that, Boostane and E85 are still options that may be less inconvenient. E85 is available 10 minutes from my work, so it's not out of the way too much, and at the quantities that cookiesowns is suggesting, aren't massive either. The E30 map is interesting, but that much E85 might be inconvenient every fill up.

I'd rather not have to do any of this, but my situation (car & fuel combination) are what they are, as you said.