The E85 Thread... Questions and Answers

[97AutoXVette]

what if i wanted to run a flex fuel setup though

Newer cars do this much easier, since they actually have a way to measure the ethanol content and adjust the ECU accordingly. We have to do this manually to the w-body platforms, as they were not equipped with the software or sensors at that time. Hence why one would have to manually check the ethanol content in a given tank of fuel, and then adjust the stoichiometric targets in the tune to really dial it in.

Note that E85 is pretty forgiving though. As in even this coming winter, when it is more like E70, than E85, I will not change my tune. I will just let it run on the rich side for several months (unless I have some issues, which I would report to this thread if so!)

[darkhorizon]

And btw flex fuel sensors are old news. They are to expensive and offer little to no value in a modern car. Gm discontinued use of them years ago.

[97AutoXVette]

And btw flex fuel sensors are old news. They are to expensive and offer little to no value in a modern car. Gm discontinued use of them years ago.

Interesting.. Any idea when they came out? I wonder why they didn't put them in the 97-03 GTPs! Wish we had them built in...

[SnowTh1ef]

Note that E85 is pretty forgiving though. As in even this coming winter, when it is more like E70, than E85, I will not change my tune. I will just let it run on the rich side for several months (unless I have some issues, which I would report to this thread if so!)

Changing tune for the winter is not necesary. Going from E85 to E70 requires about 6-7% less fuel, our PCM's can easily compensate for more than 15% in either direction. That is why you can run E30-50ish Without a tune on stock injectors if you wish.