Using 113 for the octane of ethanol, then a 93 octane gasoline with ethanol calculates to be an 8.8% ethanol content.  The summer blend for premium in my area is 3-5% ethanol.  Not sure if there is a winter blend in my part of the country.

Lorena, Texas (South of Waco)

I remembered, after my last post, what my local Marathon guy told me, (before the 15% winter fuel) that he could get 90 octane non alcohol gas for me.  He said it was premium gas without alcohol, and if the alcohol was added it was rated 93 octane.and sold in the local gas stations.  So we were  getting alcohol  in our premium gas,  but I don't know how much.

John - "The Hoosier Hurricane"

If burning premium (like me) to avoid excess ethanol (though a stock 292 should run fine on regular), likely one compensation some are missing might be increased initial spark advance (?). Could thus even gain back a few mpg (?)

6 VOLTS/POS. GRD. NW INDIANA

I don't know if the premium is 15%.  The local papers only noted that the Indiana legislation approved the 15% gas for the state, and the oil companies jumped right on that.  Happened last year.  I haven't tested for alcohol..  I realize that some of my MPG loss is related to winter driving coonditions.

John - "The Hoosier Hurricane"

H H, is that 15% across the board, like, premium fuel also?  If premium becomes 15% ethanol too, I have a suspission many of us will be doing a little carb tuning. In another area above, Ted posted  BTU numbers putting this in perspective.   My '22 Ford Ranger lost an additional 1.5 to 2 mpg this winter but I haven't tested the fuel lately for enhanol content. 

64F100 57FAIRLANE500

In my area we are blessed with 15% ethanol  in the winter months.  My Chrysler Minivan drops 3 1/2 to 4 mpg vs the 10% ethanol and summer temperatures.

John - "The Hoosier Hurricane"

Here are some early morning thoughts on the subject.

Using 19000 BTU/lb for gasoline and 12500 BTU/lb for ethanol, you end up with a 3½% reduction in energy at the 10% ethanol content levels.  If using 45 MJ/kg for gasoline and 25MJ/kg for the energy density of ethanol, then at the 10% ethanol content you lose 4½% of the energy density.  With a reduction in energy content, there will be a reduction in the fuel economy per gallon.

Supporting this was my 4 cylinder Ranger pickup that typically lost 1½-2 MPG when using the 10% ethanol blended gasoline versus non-ethanol blended gasoline.  While I have not run any ethanol versus non-ethanol tests on my 272 Y, it has seen a decrease in the fuel mileage since the premium fuel I’m using has gone from zero ethanol to 3-5% ethanol.

Lorena, Texas (South of Waco)

D. L. Racer: If after a month or so your car is very slow starting, & if you have some Lawn mower fuel or other available. Try removing the Air cleaner cover & carefully pour say 1/2 to 3/4 once of fuel in the carb venturies.  That should get the engine to start briefly & pump up some fuel to restart if needed..  


Paul

I’m stuck with ethanol blended gasoline in Taxifornia; I’ve been using Star Bright Star Tron enzyme additive for 8-10 years in my 56. In 10,000 miles I’ve not had a fuel related problem. I’m sure the gasoline in the carbs evaporate over time; if I drive the car once a week it’s one pump and start. 2 weeks it’s 2 pumps and a month takes at least 20 seconds of cranking. I use 1oz with 10-12 gallon fill up. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Further to Blacktie's post re fuel stabilization.. To stabilize for Ethanol " specifically",  use a product like Staybil "360" which is designed to mitigate it's effect on your fuel system.. There may be other similar products, but I don't have info on  them..    


Paul