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2bejustme

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With the changes in ethanol % in gasoline. Would it be wise to burn mid grade gas instead of regular in my 5.4l V2. 178,000 miles.
 

99WhiteC5Coupe

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With the changes in ethanol % in gasoline. Would it be wise to burn mid grade gas instead of regular in my 5.4l V2. 178,000 miles.


The increase in ethanol percentage does not increase or decrease the octane rating. However, ethanol has less energy per volume, compared to the same volume of gasoline (about 30% less). This results in reduced fuel mileage.

If you use mid grade gasoline that also has an increased ethanol amount, your fuel mileage will still be less than if you use gasoline without ethanol, or a lesser percentage of ethanol.
 

whtbronco

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There are stations in Virginia, Liberty stations in north west Virginia, that sell 100% gasoline. No corn syrup that gums up everything. Our fuel injected vehicles can deal with it more or less, lawn equipment and carbureted vehicles cannot and get all messed up with ethanol laced gasoline.

Using a higher octane may also reduce fuel economy aside from the ethanol. The higher the octane rating the slower it burns. If you have an engine with a high compression ratio it will need the higher octane(slower burning fuel) to prevent detonation. If the engine doesn't have a suitable compression ratio the fuel may not entirely burn before the exhaust valve opens.
 
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