I ran it for over a year and possibly 20,000 miles without an issue.

 

Yeah, with a good tune, you can probably cut some of your losses when just cruising, due to being able to run massive timing to make up for some of it, but at WOT there's no getting around the increased fuel requirement.

 

When I talked to Dave at Pwerks about E-85 vs E-47 he said that it's generally better to run E-47 if you don't have a new fuel pump because you run out of time. You have to inject a lot of fuel because of how much it has to compress.

I'm about to get tuned for E-47. I have full bolt ons and am expecting about 340 whp

 

Well, as you go up in RPM, the time in which you can spray fuel in a DI car (the injection window) decreases, so you eventually get to a point to where the pump/injectors are spraying as hard as they can, but still can't spray enough to meet requirements. If you back off of full E85, the quantity of fuel needed to meet the air-fuel mixture goal decreases, so it helps meet the fueling requirement that way, as the injectors then don't have to spray as much fuel during that window of opportunity/time.

This will probably be an obstacle in the future with high-revving DI engines. They're either going to have to lower the max RPM below what it could be, or they're going to need to raise pressure or injector size to allow for increased flow during that window of time.