[FlukeSS]

This was yesterday: Which includes 1 or 2 measurements of 100mph windspeeds. 5" snow today so can't test today.

Yes I know I need to clean the display. :x

If it matters filled Mother's car 2016 Trax LTZ with shell 87 and her gas mileage went up as well not by as much as mine but 1-2mpg. I do drive her car to work on bad weather days like today. She averages about 26-27mpg.

[ember1205]

Originally Posted by FlukeSS

This was yesterday: Which includes 1 or 2 measurements of 100mph windspeeds. 5" snow today so can't test today.

Yes I know I need to clean the display. :x

If it matters filled Mother's car 2016 Trax LTZ with shell 87 and her gas mileage went up as well not by as much as mine but 1-2mpg. I do drive her car to work on bad weather days like today. She averages about 26-27mpg.

The in-dash numbers are pretty meaningless. The only way to track MPG is manual calculation. The "drift" from my in-dash display and calculated numbers is never consistent by a fixed number OR a percentage. It's a crap system that doesn't work properly in any vehicle on the road.

[FlukeSS]

Originally Posted by ember1205

The in-dash numbers are pretty meaningless. The only way to track MPG is manual calculation. The "drift" from my in-dash display and calculated numbers is never consistent by a fixed number OR a percentage. It's a crap system that doesn't work properly in any vehicle on the road.

Do the math

162 = 1/3rd of a tank of gas x mpg

19 gallon tank

19 x .33 x 25.5 = 162 (should equal 162) actually comes to 159.86 miles. Yes I realize the gas gauge almost never measures accurately. But given that margin of error the numbers are solid. That is a margin of error of 1.7% at the time the test was done. That test was my morning commute, driving to another work facility, and then driving home over the course of a 10 hour period.

[ST1LE]

Originally Posted by ember1205

By your own statement, "all" gasoline starts out the same and differs only by additives. There are plenty of articles out there, and some heated debates here as well, that will show that even the additives don't differ except in very select cases. The differences in fuel are octane and the AMOUNT of detergents added into the fuel.

Costco is Top Tier which means the percentage content of additives meets the minimum levels. It's all I run in ALL of my vehicles and the only time I ever find variance in MPG that isn't directly the result of driving habits is when there is changeover between summer blend and winter blend fuels (winter blend fuels are much lower MPG compared to summer blend fuels).

I'm not sure if you intended to disagree with me or not, but I see no errors in your statements. Additives can be similar, some almost identical...fact still remains it is the only thing that sets gasoline apart from a molecular standpoint.

For example...the vast majority of gas stations in the pan handle of Florida source their gas from the same lone terminal in that area. All the regular gas in that terminal shares the same tank, and the premium in its own tank, meaning the grades are homogenous up until the point in which that terminal injects the gasoline with additive. Same ethanol levels, same RVP, same everything down to the molecule.

Some of our customers want 'top tier', so we give them that. But ALL top-tier from this terminal is identical too, so whether you buy it at the local Costco or somewhere else....its the same thing. We also dont use the same additives for 'top-tier' and 'branded' customers, so even if they perform similarly...they are still not the same molecularly speaking.

I'm not conveying to what degree they differ, I don't work in our PQ department, and even if I knew I would not be able to share that level of detail.

[ember1205]

Originally Posted by FlukeSS

Do the math

162 = 1/3rd of a tank of gas x mpg

19 gallon tank

19 x .33 x 25.5 = 162 (should equal 162) actually comes to 159.86 miles. Yes I realize the gas gauge almost never measures accurately. But given that margin of error the numbers are solid. That is a margin of error of 1.7% at the time the test was done. That test was my morning commute, driving to another work facility, and then driving home over the course of a 10 hour period.

You're estimating the fuel at 1/3 tank, but it's actually closer to 3/8 according to the gauge. So, "doing the math", it would be:

19 x .375 x 25.5 = 181.7... Quite a bit different than the 162 you mentioned. Gauges are not perfect and are only an estimate (when you gauge says empty, you actually still have 1-2 gallons of usable fuel left in the tank). As I've said already, the only way to know your true MPG is by hand calculating from a full fill with each tank.

Originally Posted by ST1LE

I'm not sure if you intended to disagree with me or not, but I see no errors in your statements. Additives can be similar, some almost identical...fact still remains it is the only thing that sets gasoline apart from a molecular standpoint.

For example...the vast majority of gas stations in the pan handle of Florida source their gas from the same lone terminal in that area. All the regular gas in that terminal shares the same tank, and the premium in its own tank, meaning the grades are homogenous up until the point in which that terminal injects the gasoline with additive. Same ethanol levels, same RVP, same everything down to the molecule.

Some of our customers want 'top tier', so we give them that. But ALL top-tier from this terminal is identical too, so whether you buy it at the local Costco or somewhere else....its the same thing. We also dont use the same additives for 'top-tier' and 'branded' customers, so even if they perform similarly...they are still not the same molecularly speaking.

I'm not conveying to what degree they differ, I don't work in our PQ department, and even if I knew I would not be able to share that level of detail.

I was more trying to show/understand your statements since they conflict with themselves... if all gas is the same, "down to the molecule", and all top tier gas is the same, then how could a branded fuel give better MPG than Costco since all are "the same" top tier gas? How is "branded" top tier different from Costco top tier is "ALL top-tier from this terminal is identical too"?

[ST1LE]

Originally Posted by ember1205

You're estimating the fuel at 1/3 tank, but it's actually closer to 3/8 according to the gauge. So, "doing the math", it would be:

19 x .375 x 25.5 = 181.7... Quite a bit different than the 162 you mentioned. Gauges are not perfect and are only an estimate (when you gauge says empty, you actually still have 1-2 gallons of usable fuel left in the tank). As I've said already, the only way to know your true MPG is by hand calculating from a full fill with each tank.



I was more trying to show/understand your statements since they conflict with themselves... if all gas is the same, "down to the molecule", and all top tier gas is the same, then how could a branded fuel give better MPG than Costco since all are "the same" top tier gas? How is "branded" top tier different from Costco top tier is "ALL top-tier from this terminal is identical too"?

That's my bad, I think I caused some confusion and was not as clear as I thought.

Sticking with my example, all coming from the same terminal and lets use Premium gasoline as well.

We have 3 types of premium gasoline that will come out of that terminal. They will all differ based on additive type or concentration only, and before the additive they were all the same.

1 - You have just basic generic or what we call 'unbranded', which is like your Sam's or Costco regular gasoline but it is NOT the same as their Top Tier offerings. For this, the terminal owns the generic additive and as a point they only stock 1 type of generic additive.

2 - You have your Top-Tier, which uses the same generic additive as above owned by the terminal, but it is injected at about 2.5x concentration compared to #1 above. Same exact additive molecules but just in different concentration.

3 - You have your branded like Shell, Chevron, Exxon. To be clear and to address your question, this is NOT the same as Top Tier. They use a different additive than #1 and #2 above, even made by different companies in most cases and dose levels are lower like #1 above(not 2.5x like #2).

From what I find and what I hear, the results of double or triple dosing generic additive(Top-Tier) like #2 has a very similar effect to gasoline injected with standard dose of branded additive like #3.

I think that examples 2 and 3 show that while the results are very similar the end products are different in molecular makeup. That is evidenced by the fact it takes almost 3 times the concentration of generic additive to produce similar results as single dose of branded additive.

Additionally, no matter what station you buy from in this geography of Florida pan handle, the above 3 choices are all you get. Generic from Albertsons is the same as generic from Sam's....Top Tier from Costco is the same as Top Tier from P66 etc etc. Lastly Shell gas is Shell gas, Chevron gas is Chevron gas, and Exxon is Exxon as their additives are all a tiny bit different but honestly it is so secretive we really dont know how different haha.

[Gen6cyl]

I like to get fuel from the busyiest station for freshest fuel and run fuel system cleaner about 500 miles before oil change.

[ember1205]

Originally Posted by ST1LE

That's my bad, I think I caused some confusion and was not as clear as I thought.

Sticking with my example, all coming from the same terminal and lets use Premium gasoline as well.

We have 3 types of premium gasoline that will come out of that terminal. They will all differ based on additive type or concentration only, and before the additive they were all the same.

1 - You have just basic generic or what we call 'unbranded', which is like your Sam's or Costco regular gasoline but it is NOT the same as their Top Tier offerings. For this, the terminal owns the generic additive and as a point they only stock 1 type of generic additive.

2 - You have your Top-Tier, which uses the same generic additive as above owned by the terminal, but it is injected at about 2.5x concentration compared to #1 above. Same exact additive molecules but just in different concentration.

3 - You have your branded like Shell, Chevron, Exxon. To be clear and to address your question, this is NOT the same as Top Tier. They use a different additive than #1 and #2 above, even made by different companies in most cases and dose levels are lower like #1 above(not 2.5x like #2).

From what I find and what I hear, the results of double or triple dosing generic additive(Top-Tier) like #2 has a very similar effect to gasoline injected with standard dose of branded additive like #3.

I think that examples 2 and 3 show that while the results are very similar the end products are different in molecular makeup. That is evidenced by the fact it takes almost 3 times the concentration of generic additive to produce similar results as single dose of branded additive.

Additionally, no matter what station you buy from in this geography of Florida pan handle, the above 3 choices are all you get. Generic from Albertsons is the same as generic from Sam's....Top Tier from Costco is the same as Top Tier from P66 etc etc. Lastly Shell gas is Shell gas, Chevron gas is Chevron gas, and Exxon is Exxon as their additives are all a tiny bit different but honestly it is so secretive we really dont know how different haha.

You're listing Costco as unbranded and then calling them out as Top Tier - All Costco fuels, both Costco-branded and Kirkland-branded, are Top Tier in the US, Canada, and Mexico. Costco-branded is additionally Top Tier in Puerto Rico.

[FlukeSS]

You're estimating the fuel at 1/3 tank, but it's actually closer to 3/8 according to the gauge. So, "doing the math", it would be:

19 x .375 x 25.5 = 181.7... Quite a bit different than the 162 you mentioned. Gauges are not perfect and are only an estimate (when you gauge says empty, you actually still have 1-2 gallons of usable fuel left in the tank). As I've said already, the only way to know your true MPG is by hand calculating from a full fill with each tank.

Or it means my butt dyno is more accurate than my Gas Gauge? I guessed a 1/3rd of a tank off the top of my head. And I was within 1.7% margin of error.

IF we assume the 25.5mpg is accurate and not the gas gauge. Realistically, the computer is going to know just how much gas went through those cylinders. And if the computer calculated a 25.5mpg average and also does not struggle with measuring distance considering I was on my stock wheels and tires all winter. Then my guess of a 1/3rd of a tank is probably more accurate than 3/8ths. Yes I probably just got lucky. But I also know analog gas gauges are off by about 2 gallons on average. I assumed the same for digital gas gauges.

I have driven 600-700 miles a week since the beginning of December.

During the month of February I was averaging 22mpg for 2400+ miles. All through December and January I was averaging 24-25mpg right up until I changed my oil. The only other difference was I was filling up my tank at work, rather than at home.

At of the beginning of March I switched back to my home Shell V-Power 93 in my car and after 350 miles noticed my gas mileage went up by 3mpg according to the in car gauge that is.

Now consider the mods I have on my car. The more you power mod your car the worse your gas mileage gets. Is that not generally the correct assumption?

In my case my gas mileage got better after the mods and tune over the stock tune.

Even on E85 If I drive sane I get up to 20mpg. If I drive insane I get 13-15mpg.

Physics is physics, the rest has to be the Tune on my car, weather, and/or quality of gas.

I think it would be a safe guess that we did get more snow in February than December and January, but then again I don't drive my car during bad weather?

I dunno. I just feel like the particular Shell I go to makes a difference for me.

[ember1205]

Originally Posted by FlukeSS

Realistically, the computer is going to know just how much gas went through those cylinders.

One would expect that the in-car computer would be able to properly calculate the amount of fuel being consumed, and provide accurate MPG, but it doesn't. I don't know why, I don't understand why there literally isn't a single vehicle on the road that has an accurate calc of MPG, and it's honestly frustrating.

My Silverado shows a lifetime MPG of something like 17.5 or so in the dash (I never reset Trip 2). But calculated MPG over 90k+ miles of driving and fill-ups shows the real number to be 16.7. That's about a 5% margin of error which I feel is unacceptable.

I always look at the trip rating when I fill up and compare it to what the calculate amount is. The delta between the two varies all the variance / error percentage doesn't remain the same either. I've had tanks that are very close (maybe a 1% margin) and others that are off by over 10% (truck showed 20 but calculated was under 18, for example).

[FlukeSS]

Originally Posted by ember1205

One would expect that the in-car computer would be able to properly calculate the amount of fuel being consumed, and provide accurate MPG, but it doesn't. I don't know why, I don't understand why there literally isn't a single vehicle on the road that has an accurate calc of MPG, and it's honestly frustrating.

My Silverado shows a lifetime MPG of something like 17.5 or so in the dash (I never reset Trip 2). But calculated MPG over 90k+ miles of driving and fill-ups shows the real number to be 16.7. That's about a 5% margin of error which I feel is unacceptable.

I always look at the trip rating when I fill up and compare it to what the calculate amount is. The delta between the two varies all the variance / error percentage doesn't remain the same either. I've had tanks that are very close (maybe a 1% margin) and others that are off by over 10% (truck showed 20 but calculated was under 18, for example).

That's it I'm selling my car fook GM lol

Going to buy a prius then power mod it with racing stripes and an 18" spoiler.

[Kerry]

I find the gauge to be extremely accurate. 1 tank 1 trip. wind and all kinds of factors play into it

[ember1205]

Originally Posted by FlukeSS

That's it I'm selling my car fook GM lol

Going to buy a prius then power mod it with racing stripes and an 18" spoiler.

lol

I swear.. Every Prius driver in this area drives like they are in a Camaro - and it's scary!

[TXCSSU]

Originally Posted by ST1LE

Branded(Exxon, Shell, Chevron) gas does typically give better mileage than unbranded(Costco, etc). 3 mpg is pretty impressive of a difference.

FYI, all the base gasoline is exactly the same and comes from the same source as all gas, but the additives do make a marked difference in performance.

I work for one of the big 3, and I find Chevron gives me the best mileage. I don't work for Chevron though, so I hope my boss doesn't find out HAHA.

That's what I expect someone that works for the "Big 3" to say. :P


Branded need to justify the extra costs, but as someone else has mentioned there isn't much of a difference. Hell, I used Shell Premium exclusively in one of my cars and then switched to Costco gas and didn't see any marked difference.

One big factor is the gas station itself. Some shady stations will use water, while some have some very old gas tanks (I heard about a guy pumping rusty looking gas because of how old the tank was) some use a higher concentration of ethanol (not E85 but E15-E20, etc.) Those are sometimes lower cost, but will definitely show lower performance. I used to go to a Bucee's that was about 30 miles away to fill up with pure gas (no ethanol) and didn't see a difference there either, which was a little disappointing. I did decide to use the pure gas for all my lawn equipment though, as that stupid Ethanol tears through older lawn equipment gas lines like a Mustang through a crowd at a C&C meet.