Ethanol Effects
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Ethanol Effects
Now that we're being forced to run ethanol-laced fuel in our trucks, I'm just curious as to any effects this stuff has on our valves and seats after many miles. Has anyone yanked a set of heads after 100k miles of ethanol, and how do they compare to a like mileage set run on non-ethanol? Any unusual deposits? Besides the lower fuel economy, is this something else we should be concerned with regarding ethanol?
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From: Memphis
Below is a quote from the SVTOA Memphis thread about ethanol. I know that what he has to say is geared towards performance cars but it should provide some insight into local experiences with Ethanol and tuning.
This is what I have found out doing some research for vehicle's running 10% ethanol in their fuel.
93 Octane (no ethanol) stoich air/fuel ratio is 14.64. This is perfect air fuel at idle and part throttle. Wide open throttle air/fuel for your vehicle should be between 12.8 - 13.2. This is for a bolt on vehicle without heavy engine modifications.
93 Octane (with 10% ethanol) stoich air/fuel ratio is 14.1. When ethanol is added to the gasoline, you will have to run about 5% richer in the tune. Wide open air/fuel ratio should be 12.3 - 12.7. This is for a bolt on vehicle without heavy engine modifications.
93 Octane (no ethanol) stoich air/fuel ratio is 14.64. This is perfect air fuel at idle and part throttle. Wide open throttle air/fuel for your vehicle should be between 12.8 - 13.2. This is for a bolt on vehicle without heavy engine modifications.
93 Octane (with 10% ethanol) stoich air/fuel ratio is 14.1. When ethanol is added to the gasoline, you will have to run about 5% richer in the tune. Wide open air/fuel ratio should be 12.3 - 12.7. This is for a bolt on vehicle without heavy engine modifications.
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Well that would seem to suggest the richer mixture required for running ethanol would leave more deposits, unless the ethanol helps the A/F mixture burn more completely. Which brings up another question... If ethanol leaves more deposits, could that be a contributing factor (other than the poor design ) to the 5.4 plug breakage issue?
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I cannot see ethanol having anything to do with the plugs since it happens to all 5.4's and not just the Flex Fuel versions and also, trucks with hardly any miles at all have just as much likelyhood to break as do the high mileage trucks.
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10% ethanol is in almost all brands of gas, Flex Fuel is E-85, I believe.
