My first e85 experience.

I just though I would send a little update to save others the headache. If you run e85 you really do need to test each tank, or have a wide-band hooked up so you can see when your air fuel changes drastically.

Earlier this summer when I checked my fuel from my local gas station they had switched from the winter blend 77% EtOH, to the summer blend which when I tested it was 84% EtOH. The next few tanks I just assumed it would probably stay that way for the rest of the summer (WRONG ANSWER). I've been chasing down a good tune for the summer blend ever since, not being able to quite get it. I just checked my last tank and it was 92% EtOH...my air-fuel meter was telling me it was a little lean, but I was having a hard time believing it since I was already jetting 90/100 with a PV. Well, I dropped my HSAB down from 0.036 to 0.028 and set the jets 4 steps down to compensate (86/96), ran it, AFR was about the same so I fattened it back up to 90/100. Now the AFR is reading closer to where it should be AND the car picked back up 5 hundredths (6.84 @ 99.5 at 2900' DA). I'm still a little on the lean side, so I will probably fatten it up 1-2 more steps.

So anyway, to make a long story short, check every tank or drum if you go that route.