Will E30-E40 Ethanol Blends Damage The FiST Engine?

[V_2]

I imagine our cars will do just fine. I ran e30 for a little over 20k miles on a 2004 Nissan with no problems or fuel system degradation, and that was after 150k miles of running 93. I switched maps and ran a tank or 2 of straight 93 E10 every couple of months.

From my limited understanding, running a higher ethanol-concentrated blend may be better for the internal engine components due to (relatively) less heat generated during combustion, lower cylinder temps, and cleaner exhaust byproducts.

Just use the same precautions you are supposed to use with E10 that others have already touched on. Don't let the tank sit for months without use. I've heard ethanol can go bad in 30-60 days if left sitting. Keep as much fuel in the tank as possible to help prevent condensation with day/night/seasonal temperature swings.

 

[Wimp Lo]

A gas tank is kind of vented, we have an evaporative emissions system that keeps it sealed unless there is sufficient pressure or vacuum to open the valves.

The Evo that sat for two years was not sitting in humid air, and being garaged, I'm sure it saw less temperature swing than anything stored outdoors. It is very possible that the gas tank vented a little up until its warmest day and then was essentially sealed.

 

[OffTheWall503]

I think I would be more concerned with emissions components failing prematurely.