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Grumpy Bears 2015 Silverado 2WD


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April 2021 Fuel Report

 

27.65 mpg Lifetime Running Average.

 

26.53 mpg Year to Date 2017

25.99 mpg Year to Date 2018

27.37 mpg Year to Date 2019

25.71 mpg Year to Date 2020

26.94 mpg Year to Date 2021

 

 

image.png.72be1b8af83e12f037cfb18078fba3b3.png

 

27.20 mpg April 2021 

27.68 mpg April average all years. 

 

Note: 0W20 was good for a 4.6% increase in fuel efficiency over 10W30 or 1.28 mpg year over year. 

 

 

 

 

 

 

 

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5/6/2021

 

This will be a bit of a rant. 

 

The current run up in gas prices has made E85 attractive for the first time since I've owned Pepper. Well...sort of. 

 

I expect most price E-85 against 93 E-10 and base than on an octane basis. And I would find that a valid comparison IF Pepper required 93 octane fuel...but she doesn't. 87 is more than enough so....E-85 needs to be priced 30% below the cheapest 87 in my area to make that economically viable. And boy is it close. That is ,would be if it were not for COSTCO and my 4% discount and the fact COSTCO does not offer E-85 as an option. 

 

Then there is the fact that local stations gouge E-85 pricing. Local Pilot Truck stop has the cheapest E-85 within 100 miles at $2.09. Average 87 pricing is $2.99. But COSTCO is $2.85 and with the 4% discount $2.74 meaning the price of E-85 would have to be $1.92 to break even. 

 

Here's the hair in the oil. Both stations are not really close. COSTCO is 18 miles away and Pilot 25 miles away. Every other station in the area that carries E-85 65 cents a gallon or more above Pilot and every other station pricing 87 35 cents a gallon over COSTCO. At those prices I can burn a gallon of gas or more on a empty tank, pay tolls and still come out right side up. Just takes time and adds miles. 

 

I'd really like to try E-85 but Pirates and Greedy Thieves are going to hinder that. Iowa is 100 mile away and the cheapest E-85 normally as the local gas tax is hideous and yet even that is a non starter at a dime a gallon over Pilot. However local 87 pricing is cheaper than even COSTCO. Okay unless I go to Davenport COSTCO where I could buy at $2.48 a gallon. But that too is 100 miles away. 

 

A 26 gallon tank limits options. Boy do I wish I had a 36 gallon tank. 😉 

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Game On! 

Flex Fuel

 

5/7/2021 136,041 miles. 

 

Took on 15.266 gallons of E-85. Pepper has a 26 gallon tank. Tested at 79%. ECU is saying this gave me an E-50. Took it on a 125 mile loop and all I can say so far is there is not one single trace of knock ******. Something I'd get a trace of even with pure E-0 93 Phillips pump premium. This a 59/41 split. The math worked. The Scan Gauge II looks accurate.  

 

Cost for the blend was $2.471 per gallon mixed. Last tank of 87 being $2.999 and todays E-85 $2.099.

 

Of course I can not confirm any data until the next fill but on board Linear Logic meter told me a shade over 29 mpg for the loop. I did start 'hot'. Drove 25 miles for the E-85. That would work out to about 8-1/2 cents a mile. Current pricing and mileage with 87 E-10 has been running 10 cents a mile. 

 

I never trust single data points so....I'll stay with it for awhile and see how it shakes out. 

 

Other than being surprised by the mileage and a total lack of spark knock as indicated by the knock sensors there was zero other tangible difference I can report. The system transitioned flawlessly and undetectably by seat of the pants Instruments seemed to indicate less timing was needed overall. Part of the tables I expect.  

 

I will be targeting 50% Ethanol blending with 87 E-10. Seem cost effective. So far.... IS there another shoe I hear dropping?

 

 

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5 hours ago, Grumpy Bear said:

Took on 15.266 gallons of E-85. Pepper has a 26 gallon tank. Tested at 79%. ECU is saying this gave me an E-50. Took it on a 125 mile loop and all I can say so far is there is not one single trace of knock ******. Something I'd get a trace of even with pure E-0 93 Phillips pump premium. This a 59/41 split. The math worked. The Scan Gauge II looks accurate.  

 

Cost for the blend was $2.471 per gallon mixed. Last tank of 87 being $2.999 and todays E-85 $2.099.

 

Mine gets its best gas mileage with a mix of E85 and gasoline or E15.  Sixteen to twenty-two percent nets my best gas mileage and lowest cost per mile to operate.  After you play with running full dosages of E85, you may want to try that out.

 

Mine loves FlexFuel, like cheap race gas, the motor loves it.

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E-85 Experiment, Cont.

 

5/8/2021

 

2265 miles averaged 27.27 mpg at a unit cost of $2.736 per gallon for a cost of 10.00 cents a mile. That's the bench mark. 

 

Round one bend at 50% Ethanol. 375 miles calculated to 24.85 mpg at a unit cost of $2.45 per gallon. Cost 9.9 cents per mile. A savings of 1/10th of a cent per mile. Meh! 

 

While this looks like a bust nothing I do goes without learning a valuable lesson. This time the lesson was concerning the Scan Gauge II I use. When you calibrate this thing you start at zero offset and run a tank. The meter will tell you what it thinks it used and the pump will tell you what it really used. The difference is the offset. You change what the meter said to what the pump said and it tells you what percent the adjustment is. Seem simple enough except it is a moving target. I though the largest variable was the pumps auto shut off. They vary. Even the same pump on different days...it changes. Then there is expansion in the trucks tank. Varies with temperature. But by using some stats I get it within a tenth of a gallon. This last the summer or the winter where there is a shift and we rinse and repeat. Head scratcher until today. 

 

The trucks ECU has a meter and that meter has a 'density' correction based on ethanol percentage. The Scan Gauge does not access to that information. Just he meters output. So when fuel density changes so does the meters error. Light bulb moment!! Density is not just a function of composition but temperature as well. Twice a year the fuel composition changes so the meters accuracy does as well. The came to my attention when during todays run the Gauge was showing a usage of 12.2 gallons but the trucks fuel gauge was well under 1/2 and the ECU output was 43% or about 15 gallons. It also happens to be the difference in density between E-10 and E-50. Both showed 29.2 mpg. This happened once more at the fill up. 70 miles home again 29.2 mpg but this time with 19% Ethanol. So today I learned something about my instrument that is invaluable. 

 

Now of course I freaked not realizing what was happening so stopped the test early and filled with E-0 91 octane at one silly cost that resulted in a mix that tested 19% ethanol. The target of the next tank. (Swathdivers suggestion taken). 

 

To be fair I calculated the cost per gallon for this as if I was doing so at the Petro/Fina where I buy the E-85 instead of using the premiums much higher cost to reach the same ethanol content. AND I did not adjust the meter for any variation knowing that it would take months to get an accurate 'instant number'.

 

Another thing that came from this was learning that while the tank is indeed a 26 gallon tank the numbers are telling me the fuel pump and dead air space takes up 1 gallon of that volume. This is important as the meters base correction is based on tank volume.  3.8%. 

 

Conclusion:

 

1.) So far we are break even on cost per mile but lost significant range. 

2.) To be accurate I would need to invest in a graduate cylinder and stopper for Ethanol concentration testing and a lap top to run the calculation quickly enough to no hold up the world. 

3.) I would also need to hand blend each batch. 

4.) These cost are based on 'Best Pricing' which means travel of 18 to 25 miles for each fill up doubled. (round trip) Tolls would have to be factored. 

5.) Not looking promising at all. 

6.) The only plus so far is zero knock ******. 

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Useful Information 

 

This chart if based on BTU per gallon.

Find Ethanol test percent on lower scale

Follow up to blue line then left to loss percentage

 

image.png.4792cd645552e47d63d09775c2cc5905.png

 

What it means.

 

If your tank test 75% Ethanol and your normal fuel is 10% the subtract 3% from 26%. 

Your E-85 will need to be 23% cheaper than the E10 to break even.

 

 

Things that will make this vary are: 

Actual BTU content of the mix gas which varies about 2% season to season

AND

If the octane is high enough to prevent spark ****** then it may do a few percent better.  

Edited by Grumpy Bear
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On 5/8/2021 at 9:19 PM, Grumpy Bear said:

E-85 Experiment, Cont.

 

5/8/2021

 

2265 miles averaged 27.27 mpg at a unit cost of $2.736 per gallon for a cost of 10.00 cents a mile. That's the bench mark. 

 

Round one bend at 50% Ethanol. 375 miles calculated to 24.85 mpg at a unit cost of $2.45 per gallon. Cost 9.9 cents per mile. A savings of 1/10th of a cent per mile. Meh! 

 

While this looks like a bust nothing I do goes without learning a valuable lesson. This time the lesson was concerning the Scan Gauge II I use. When you calibrate this thing you start at zero offset and run a tank. The meter will tell you what it thinks it used and the pump will tell you what it really used. The difference is the offset. You change what the meter said to what the pump said and it tells you what percent the adjustment is. Seem simple enough except it is a moving target. I though the largest variable was the pumps auto shut off. They vary. Even the same pump on different days...it changes. Then there is expansion in the trucks tank. Varies with temperature. But by using some stats I get it within a tenth of a gallon. This last the summer or the winter where there is a shift and we rinse and repeat. Head scratcher until today. 

 

The trucks ECU has a meter and that meter has a 'density' correction based on ethanol percentage. The Scan Gauge does not access to that information. Just he meters output. So when fuel density changes so does the meters error. Light bulb moment!! Density is not just a function of composition but temperature as well. Twice a year the fuel composition changes so the meters accuracy does as well. The came to my attention when during todays run the Gauge was showing a usage of 12.2 gallons but the trucks fuel gauge was well under 1/2 and the ECU output was 43% or about 15 gallons. It also happens to be the difference in density between E-10 and E-50. Both showed 29.2 mpg. This happened once more at the fill up. 70 miles home again 29.2 mpg but this time with 19% Ethanol. So today I learned something about my instrument that is invaluable. 

 

Now of course I freaked not realizing what was happening so stopped the test early and filled with E-0 91 octane at one silly cost that resulted in a mix that tested 19% ethanol. The target of the next tank. (Swathdivers suggestion taken). 

 

To be fair I calculated the cost per gallon for this as if I was doing so at the Petro/Fina where I buy the E-85 instead of using the premiums much higher cost to reach the same ethanol content. AND I did not adjust the meter for any variation knowing that it would take months to get an accurate 'instant number'.

 

Another thing that came from this was learning that while the tank is indeed a 26 gallon tank the numbers are telling me the fuel pump and dead air space takes up 1 gallon of that volume. This is important as the meters base correction is based on tank volume.  3.8%. 

 

Conclusion:

 

1.) So far we are break even on cost per mile but lost significant range. 

2.) To be accurate I would need to invest in a graduate cylinder and stopper for Ethanol concentration testing and a lap top to run the calculation quickly enough to no hold up the world. 

3.) I would also need to hand blend each batch. 

4.) These cost are based on 'Best Pricing' which means travel of 18 to 25 miles for each fill up doubled. (round trip) Tolls would have to be factored. 

5.) Not looking promising at all. 

6.) The only plus so far is zero knock ******. 

To me if it was a break even or even a slight increase in cost I would run E-85 every time.  The benefits of higher octane and such a cleaner burn in the cylinders to me is worth it. 

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23 minutes ago, Black02Silverado said:

To me if it was a break even or even a slight increase in cost I would run E-85 every time.  The benefits of higher octane and such a cleaner burn in the cylinders to me is worth it. 

 

Would be to me too IF the locals weren't playing games with the pricing. Most stations within 50 miles of me are charging near 87 octane pricing. Only Petro's price is workable and I can't live on 1 station 25 miles away. :dunno: 

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E85 Experiment 

 

5/10/2021

 

You do know it is impossible to know what a tank of a different fuel "would have done" under the current test conditions, right? 

 

So we follow the chemistry. Same station. Same tanks. Same BTU content. Safe assumption. 

 

Just finished the 19% blend over nearly the same distance and got the same results. Cost per mile is within mills of the same cost. Fractions of a cent. 

 

Here's the 411 on this. "They" have it figured out and I mean to to the penny. The pricing is set to give the same result no matter what based on cents per mile. You are not going to win this game anymore than buying a hybrid. In that case the savings in fuel used over the expected live of the vehicle is the difference in strike price at purchase. That is to say if that car were to save you say $10,000 over it's life that cost is added to the buy price of the car at sale. The OEM will keep every last cent you might have saved by buying that car. The oil industry will keep every last cent saved in fuel economy difference between ethanol and gasoline. So how do you win this? 

 

Shift your point of reference from raw MPG to cost per mile PER octane requirement.

 

Wait!! Cars/trucks the require 91+ octane are not 'normally "Flex Fuel" ready. Let that sink in a second. If they were you might be able to win this rigged game. 

 

Heads up. Most stations are NOT selling E-85 at a break even price to 87 octane. Fact is they are not selling at a break even price based on octane either. You have to actually do the math and know what that math is to win this game.

 

Here's the bet that Ethanol, Big Oil and OEM manufactures and making and every time...they expect you to do the 'right thing' for the environment while they continue to the the "wrong thing" to maximize profits. That kids is some sick crap. 

 

For any given amount of fuel consumed a set amount of BTU's will be required. That means that efficiency differences can NOT be figured on anything but BTU values of the fuel used and the cost for those BTU's. You MUST use the cost of the fuels blended on tank #1 for ALL test and blends to eliminate cost per gallon changes during that test. The fuel has no idea what the holder is charging for them. Differences in mileage must be calculated on  the delta in BTU's for the SAME test. 

 

When I hold these basics I find the difference in cost per mile to be within fractions of a cent...mills. However if I base it on equivalent octane and that octane number exceeds 90 (R+M)/2...then things tilt in your favor. Provided your flex fuel capable. Problem for Pepper is...she runs just fine on 87. 

 

A tank or two more to lower Ethanol to 9% and I'm done with this test.

 

What I learned.

 

Buy the cheapest Top Tier 87 octane fuel you can find.

 

Yea yea assuming you can run 87.

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