Consensus is a percent or two won't hurt, but it's recommended to upgrade pump if going e50 or above, especially for e85. That's what I've heard and read.Gotcha, makes sense. I was assuming running way over what the car is tuned for without the supporting parts/tuning would lead to damage.
I guess the consensus is that a percent or two over e50 until you re-mix shouldn't be an issue right?