False. 30% is generally the rule of thumb, but it varies by E% of your pump gas and of your E85. Of course you fine tune from there, but 50% is way too much. Even E100 has 65% of the energy content of gasoline with E0. If you are going from E10 as is typical for pump gas to E85, you would need to increase fuel by volume even less. I recently switched from pump gas to 50/50 pump and E85 to full E85 and it was nowhere near 50%. Infact 50% would mean i wouldnt even have enough pump or injector.
Official documentation: "1 gallon of E85 has 73% to 83% of the energy of one gallon of gasoline (variation due to ethanol content in E85). 1 gallon of E10 has 96.7% if the energy of one gallon of gasoline." see attached
Energy content of fuels
Fossil and Alternative Fuels - Energy Content (engineeringtoolbox.com)
conventional gasoline, 34, 613 MJ per cubic M
Ethanol 23,531
So that's an extra 47% you need for E 100 at lambda 1
If your E85 is 85% then you're looking at about 40% more.
As far as volume goes at full boost, it depends on whether you're doing the comparison with race fuel or pump fuel.
Comparing to low octane pump, you run it extra rich so the difference in required volume is a lot less than with race fuel.
if your 1 gallon of E100 has 65% the energy content as you say above then you need 54% more by volume.
If your 1 gallon of E85 has 73% the energy as you say above then you need 37% more
If it's got 83% then you need 20% more
BTW both my cars are on their original fuel filters.
Why replace them?
Pressure and flow tests along with voltage and amperage tests show that they don't need changing.
Go think on that for a while?
It always beats trying to fix problems using nothing but guesswork.
