Best octane fuel for fuel eceonomy? (5.3L only)

[thompsoj22]

Octane is about detonation and pre-ignition prevention, not about energy per gallon.

Example: Methonal has about half the BTUs(energy) per gallon of Gasoline. Methanol naturally has a very high octane rating even though it has half the energy.

Just the mention of methanol gives me "speedway envy" 10 years ago i bought a 500cc jawa and tried my hand at learning to ride one. I still miss that bike! Absolutely violent acceleration, And the only bike you will ever ride that will accelerate/loop if you let off the gas incorrectly? The engine ran super cool but they all have the potential of violent endings if/when they come apart. I never realized low BTU's but high octane enabled the average 16.1 compression ratio's. Wifey is gonna be pissed when she sees another one in the garage someday! Ill hear the "remember your a dad now!"

 

[BG1988]

Octane is about detonation and pre-ignition prevention, not about energy per gallon.

Example: Methonal has about half the BTUs(energy) per gallon of Gasoline. Methanol naturally has a very high octane rating even though it has half the energy.

Sometimes the 91 oct will still be on summer fuel.. look at the price 89 and 91 is priced a bit higher so 87 winter will be at 2.89 and 3.09/3.29


( most stations will refuse delivery of 91 winter grade )
while 87 is on winter fuel, winter fuel has less BTU then summer fuel

 

[91RS]

Proof? Fuel tankers don't just show up at gas stations like door-to-door salesman.

 

[iamdub]

Well, I like my fuel to deliver the most horsepower, the best gas mileage at the least possible cost!

Full strength E85 is great, engine runs cooler, smoother, shifts better even and makes more power. I've never intentionally ran 87 or anything less than 93 in my vehicles.

Last year we burned 21 tanks of 93 with an alcohol level of 10% or less. Truck averaged 15.5 MPG which cost an average of nineteen cents a mile to drive.

Burning mixes of 87 or 93 or E15 with E85 with an alcohol content of between 11% and 20% also delivered an average of 15.5 MPG which cost an average of seventeen cents a mile to drive.

Same mix but with an alcohol content of between 21% to 30% cost the same but delivered 14.8 MPG.

E85 was cheap last year and the truck averaged fifteen cents a mile with 12.4 MPG.

Our DICs let us calculate all kinds of data and efficiencies:

View attachment 252837

View attachment 252838

PPG = Price per Gallon
CPM = Cost per Mile
MPG = Miles per Gallon
GPH = Gallons per Hour
MPH = Miles per Hour
AC% = Alcohol Content Percentage

I wasn't sure if I should've replied to a post in your "Useless Information" thread, but I couldn't find it so I'll ask here:

I've been filling up (half tanks, actually, but from nearly empty) at a RaceTrac on my side of the river since it's the closest E85 to me. I was playing with my scanner Sunday evening and it showed my alcohol content to be 22%. I know E85 is often less than 85% alcohol, but this is excessive. I'm considering manually testing the fuel to compare. Is there anything I could check or do? I believe mine calculates the alcohol content based off of other sensor data rather than from a composition sensor. I got this reading while sitting in the driveway with it idling for about 30 minutes, so it was in closed loop. I fueled up Friday evening and the station is about 22 miles away, so it had plenty of time to adjust after the refueling.

 

[79jasper]

Many cheaper kits out there. I think I'll try one of these.
https://www.amazon.com/dp/B073HLSVHX/ref=cm_sw_r_cp_apa_i_z4pgFbXZ9E0G2


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[George B]

Many cheaper kits out there. I think I'll try one of these.
https://www.amazon.com/dp/B073HLSVHX/ref=cm_sw_r_cp_apa_i_z4pgFbXZ9E0G2


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Thats pretty slick. You can also do this.
https://www.delphiautoparts.com/usa/en-US/resource-center/how-test-alcohol-content-gasoline

 

[iamdub]

Many cheaper kits out there. I think I'll try one of these.
https://www.amazon.com/dp/B073HLSVHX/ref=cm_sw_r_cp_apa_i_z4pgFbXZ9E0G2


Sent from my SM-N960U using Tapatalk

I have this one in my cart. The etched graduations won me over: https://www.amazon.com/Etched-Ethan...H8EGFEK2Q86&psc=1&refRID=76XS37BK4H8EGFEK2Q86

 

[iamdub]

Thats pretty slick. You can also do this.
https://www.delphiautoparts.com/usa/en-US/resource-center/how-test-alcohol-content-gasoline

To avoid paying $15 for a test tube with a lid, I was looking up glass vials to make my own for a fraction of the cost... Meh. I ain't got time for that.

 

[George B]

To avoid paying $15 for a test tube with a lid, I was looking up glass vials to make my own for a fraction of the cost... Meh. I ain't got time for that.

I agree.

 

[George B]

One of these little test tubes is great but you will want to test the fuel as it leaves the tank. Would you tap some off the fuel rail at the test port?