Better fuel mileage with synthetic?

[OVERKILL]

Originally Posted By: OilGuy2

Toyotas are often affected by carbon deposits on the piston top, combustion chamber, valve faces and upper rings because of the nature of their fuel injection system. The carbon deposits occur primarily when the engine is cold and is a bigger problem where winters are long and the trips are short.

MMO will remove those deposits in a single treated tankful of fuel while fuel injector cleaners will not. I had a 1987 Toyota Camry for 22 years (2.0L SOHC) and carbon was an issue due to cold winters and short commutes. MMO was the cure. Toyota's cure was to tear down the engine and clean it.


So you personally tore down or examined in detail with either a boroscope or by removing the head, these carbon deposits, then, on the exact same engine, ran ONE TANK of gasoline with MMO in it and performed the same procedure and it was spotlessly clean?

Just trying to get a handle on your claims here.....


Quote:
Oil in the sump does not reach the combustion chamber or the top rings very well unless an engine is pretty worn which is why the MMO is added to the fuel.


The value of a UCL (which is what you are alluding to here) is a topic that has been debated extensively on here. The longest lived engines; those used in taxi and limo service never see any UCL. I've torn down numerous Ford Windsor engines with "like new" bores, many of which were just run on regular run-of-the-mill oil. Those run on synthetic were spotless. No MMO in the oil or gas, no UCL of any kind.

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MMO also has ester type aromatics that will adhere to engine metal.


According to who? I've never seen this claim made before.

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Because of its penetrating nature, it will get into very tight areas such as valve guides and help protect against wear. One of the obvious advantages of MMO is that it is very inexpensive: slightly more $$ than a quart of Dino but less than a quart of synthetic and a little goes a very long way. Its characteristics are unique and different than other oils and other cleaners.


Do you have any proof of this? IE, fleet testing of some sort, extended controlled tear-down tests or?

Quote:
I make no claims about MMO regarding fuel efficiency. A very small amount makes oil flow more easily and it makes engines cleaner: top to bottom. It follows that makes oil less resistant to circulation through the engine and that circulation improves temperature uniformity and reduces friction. But that doesn't mean it saves fuel. There is always 0W-20 or 0W-30 to use instead but they do little or nothing for the combustion chamber, piston top or valve faces.


Of course MMO makes oil flow easier: It is a mild solvent/light oil. If you added WD40, it would make oil flow easier as well. It doesn't mean it is a good idea. And WD40 is also a penetrating lube with various "mythical" properties.....

Quote:
MMO is primarily used in aviation, for which it was designed. Since your car does not fly, you should not try it. Big Oil would agree that all possible aids to fuel efficiency should be removed from the marketplace, other than their oil.

Nothing ventured, nothing gained.


In the engines I've torn down, I have never seen anything that would indicate a need to use MMO or any other "magic elixir". These engines are run on good oil changed at reasonable intervals and driven hard when warmed up. Its a process that has worked for me and many others.

 

[Garak]

Originally Posted By: OilGuy2
Here's MY agenda: help the little guy realize better gas mileage and less engine wear. Secondary agenda: rebuttal the naysayers.


That's fine, but it doesn't change the fact that conventionals do well in all kinds of engines, including American V8s, even under severe service. I've run a lot of Chevrolet small blocks (and a few Ford 5.0s and 4.6s) on conventional in fleet use for millions of miles. All these were on conventional only (Quaker State) meeting engine specifications of viscosity and API/ILSAC requirements. There were no upper cylinder lubes or anything like that. They tended to run forever. And, I was extending OCIs to 6,000 miles, when such a thing was unheard of.

That experience knocked me off the synthetic bandwagon.

 

[rcy]

Originally Posted By: OilGuy2
Originally Posted By: rcy
Originally Posted By: OilGuy2

That's what the doctors said to Louis Pasteur when he recommended that surgery be performed with sterile hands and sterile instruments on a sterile table. So the Army Surgeons continued to drink and smoke while performing surgery during the American Civil War and surgeons did not adopt Louis Pasteur's recommendations for several decades.



I think you mean Joseph Lister. And I have no idea how this relates to anything being discussed. Lister actually peformed experiments - he didn't just say that disinfection prevented infection out of the blue.



Lister discovered "Listeria"...the bacteria and disease that affects people who drink unpasteurized milk. Pasteur was the one that came up with the process (pasteurization) to make milk safe without the risk of contracting a deadly disease that almost always killed its victim, or an unborn fetus.


Yes, but you weren't talking about pasteurization in your post. You stated "That's what the doctors said to Louis Pasteur when he recommended that surgery be performed with sterile hands and sterile instruments on a sterile table."

However, it wasn't Pasteur who recommended this (sterile instrument/hand washing), it was Lister.

http://en.wikipedia.org/wiki/Joseph_Lister,_1st_Baron_Lister

 

[rcy]

Originally Posted By: OilGuy2


rcy: I'm sorry you felt motivated to make demands for "data" when you had none to support your disagreement. Thank you for admitting that. Please stop misrepresenting my post. We can agree to disagree and let each decide according to their own preference.

You want some proof, some "data" that supports synthetics over mineral oil? The finest, most expensive cars in the world come off the assembly line with synthetics. The racing world thrives on synthetics. Military and commercial aircraft use synthetics. Brakes and transmissions converted to synthetics decades ago. If it wasn't for synthetics, a lot of pole dancers would be out of a job.


You're missing the point of my post - which is that you have no data to back up your claims. You're posting your opinion. I don't need any data to back up my claims, because I haven't made any claims, except the one that your post is just your opinion without any hard facts. I don't need any data to prove that...it's right there for everyone to read.

I haven't claimed anywhere that synthetic oil is better than conventional oil or vice versa.

Further, all that you claim in this latest post (about synthetics in new cars, racing etc.) is not data or proof that synthetic is better than dino. It's just an observation that synthetic is being used in the finest cars, racing etc. etc.

 

[KrisZ]

Originally Posted By: OilGuy2
Here's MY agenda: help the little guy realize better gas mileage and less engine wear. Secondary agenda: rebuttal the naysayers.


I will let you go on with your "quest" then. Good luck, but you won't get too many followers here with a bunch of half baked theories, backed up by half baked opinions.

 

[Durango]

Originally Posted By: Merkava_4
You guys that have switched from conventional to synthetic, has your fuel mileage improved at all?


Merkava_4,

Yes on long trips I have noticed a a pretty good improvement using my over head computer. In the city I see no difference.

Durango

 

[Radman]

Originally Posted By: CATERHAM
You can attribute 2% at most to the M1 0W-30. The remaining 4-5% is something else, likely a measuring error; it doesn't take much.


Most synthetic oils are thinner than their mineral oil counterparts. The less viscosity you have the better the fuel milage to the point of broken oil film. Hence why people think syns give better milage.

 

[Coprolite]

Ironically, my fuel economy dropped slightly after my last change from PP 5w30 to M1 AFE 0w30. At Texas temps, I believe the 0w30 is more viscous. The last few tanks on the car with the Nissan Ester 5w30 was better economy than the PP. However, the Nissan oil is known to shear below grade which could help explain that differential.

The Mobil 1 was put in just around the time that the gas stations were switching fuel formulation in September. However, I saw no difference in economy during the spring fuel changeover with the PP.

No general assumptions seem to apply to this car.

 

[CATERHAM]

Originally Posted By: Coprolite
Ironically, my fuel economy dropped slightly after my last change from PP 5w30 to M1 AFE 0w30. At Texas temps, I believe the 0w30 is more viscous.

M1 0W-30 will be very marginally lighter at all temp's due to it's lower HTHSV of 3.0cP vs 3.1cP for PP and their VI's are very close; 166 vs 169.

 

[OilGuy2]

Originally Posted By: OVERK1LL
Originally Posted By: OilGuy2

Toyotas are often affected by carbon deposits on the piston top, combustion chamber, valve faces and upper rings because of the nature of their fuel injection system. The carbon deposits occur primarily when the engine is cold and is a bigger problem where winters are long and the trips are short.

MMO will remove those deposits in a single treated tankful of fuel while fuel injector cleaners will not. I had a 1987 Toyota Camry for 22 years (2.0L SOHC) and carbon was an issue due to cold winters and short commutes. MMO was the cure. Toyota's cure was to tear down the engine and clean it.


So you personally tore down or examined in detail with either a boroscope or by removing the head, these carbon deposits, then, on the exact same engine, ran ONE TANK of gasoline with MMO in it and performed the same procedure and it was spotlessly clean?

If you've been maintaining the engine, one tank of treated gasoline should clean up carbon deposits. If you've not been maintaining it, or have wrongly assumed that there is never any need to deal with carbon build up, then it may take several tanks of fuel over several weeks to get all the carbon off the moving and stationary parts in the top end. Its takes certain conditions to generate the carbon build up. Long freeway commutes tend to remove the build up but not everyone uses the freeway every day.

Quote:
Oil in the sump does not reach the combustion chamber or the top rings very well unless an engine is pretty worn which is why the MMO is added to the fuel.


The value of a UCL (which is what you are alluding to here) is a topic that has been debated extensively on here. The longest lived engines; those used in taxi and limo service never see any UCL. I've torn down numerous Ford Windsor engines with "like new" bores, many of which were just run on regular run-of-the-mill oil. Those run on synthetic were spotless. No MMO in the oil or gas, no UCL of any kind.

New York City taxicabs had to change to 7 quart sumps and oil coolers to stop the generation of sludge caused by the breakdown of regular Dino because it could not handle the heat of the engines with long periods of running and idling and high temperature thermostats. Don't know the exact company but Kendall Oil was the oil provider and their engineers determined that the oil was not the problem: the engines had changed and were producing so much heat the oil was breaking down in the camshaft tunnels. Now, how do you think all that sludge was cleaned out of all those taxicabs? Teardown with every oil change? There are many products besides MMO that can remove the sludge and you can be pretty sure they used something besides wrenches.

Quote:
MMO also has ester type aromatics that will adhere to engine metal.


According to who? I've never seen this claim made before.

According to the physical Laws of Chemistry! The "wintergreen" smell is due to "oil of wintergreen" which is also known as methyl salicylate. Methyl salicylate is an "ester".

Quote:
Because of its penetrating nature, it will get into very tight areas such as valve guides and help protect against wear. One of the obvious advantages of MMO is that it is very inexpensive: slightly more $$ than a quart of Dino but less than a quart of synthetic and a little goes a very long way. Its characteristics are unique and different than other oils and other cleaners.


Do you have any proof of this? IE, fleet testing of some sort, extended controlled tear-down tests or?

Proof of low cost? Go to Wal-mart and check it out. Proof it works? Google "Marvel Mystery Oil" and read every post on every website that pops up. See what owners, mechanics and engineers in automotive and aviation have to say about MMO. Do your homework if you are going to say something doesn't work!

Quote:
I make no claims about MMO regarding fuel efficiency. A very small amount makes oil flow more easily and it makes engines cleaner: top to bottom. It follows that makes oil less resistant to circulation through the engine and that circulation improves temperature uniformity and reduces friction. But that doesn't mean it saves fuel. There is always 0W-20 or 0W-30 to use instead but they do little or nothing for the combustion chamber, piston top or valve faces.


Of course MMO makes oil flow easier: It is a mild solvent/light oil. If you added WD40, it would make oil flow easier as well. It doesn't mean it is a good idea. And WD40 is also a penetrating lube with various "mythical" properties.....

WD40 is not so mythical. Its primary carrying agent is kerosene which would attract water and cause other issues.
MMO makes oil flow easier for another reason. It dissolves and removes fullerenes.

Quote:
MMO is primarily used in aviation, for which it was designed. Since your car does not fly, you should not try it. Big Oil would agree that all possible aids to fuel efficiency should be removed from the marketplace, other than their oil.

Nothing ventured, nothing gained.


In the engines I've torn down, I have never seen anything that would indicate a need to use MMO or any other "magic elixir". These engines are run on good oil changed at reasonable intervals and driven hard when warmed up. Its a process that has worked for me and many others.


Well if you are tearing down engines in the transportation industry, they get a different kind of use than Soccer Mom cars used in the city and the suburbs. If you continually maintain the engines and the driving scenario doesn't cause problems with short trips and prolonged cold weather aggravating carbon build up, MMO may not be needed for that reason. But how do you dissolve the fullerenes in the engine? How do you keep them from plugging up your oil filter and blocking your oil gallery?

Now that I've answered all your questions and addressed your disagreements above, here is something for YOU to do:

Your assignments in self-education are as follows:

Google "Marvel Mystery Oil" and read several dozen posts on several websites. Try TDI and Maxima. There are plenty to check.
Get a "feel" for what you arguing against because there is a lot of anecdotal evidence readily available that says you need to widen your point of view, if you just look for it.

Look up "fullerenes" so you know and understand what they are and that they develop in an engine because it is the nature of the element carbon to bond with itself.

Also, while you are at it, look up 1,2-dichlorobenzene and 1,4-dichlorobenzene. Take note of the temperature at which they evaporate and also what it is that they are capable of dissolving. Then imagine how those two properties could be used in combination and where that combination would work.

Now you know two of the three principal things that Marvel Mystery Oil can do and why it may be a pretty good thing to add once in while if the usage scenario is one that builds up carbon in the engine.

I'll leave the third thing up to you to find out. When you know what it is, you can tell everyone about it.

 

[ledslinger]

Isn't fullerenes gremlin food?

 

[OVERKILL]

Originally Posted By: OilGuy2

If you've been maintaining the engine, one tank of treated gasoline should clean up carbon deposits. If you've not been maintaining it, or have wrongly assumed that there is never any need to deal with carbon build up, then it may take several tanks of fuel over several weeks to get all the carbon off the moving and stationary parts in the top end. Its takes certain conditions to generate the carbon build up. Long freeway commutes tend to remove the build up but not everyone uses the freeway every day.


You didn't answer my question. I've taken apart high mileage engines before. Have you?

Quote:

New York City taxicabs had to change to 7 quart sumps and oil coolers to stop the generation of sludge caused by the breakdown of regular Dino because it could not handle the heat of the engines with long periods of running and idling and high temperature thermostats. Don't know the exact company but Kendall Oil was the oil provider and their engineers determined that the oil was not the problem: the engines had changed and were producing so much heat the oil was breaking down in the camshaft tunnels. Now, how do you think all that sludge was cleaned out of all those taxicabs? Teardown with every oil change? There are many products besides MMO that can remove the sludge and you can be pretty sure they used something besides wrenches.


Have you seen the Exxon-Mobil New York taxi test? It doesn't quite jive with what you are saying above.

Quote:

According to the physical Laws of Chemistry! The "wintergreen" smell is due to "oil of wintergreen" which is also known as methyl salicylate. Methyl salicylate is an "ester".

So because it smells like wintergreen (and so does toothpaste and Listerine) it has a significant ester component? It couldn't just be added to make it smell that way eh?

Proof of low cost? Go to Wal-mart and check it out. Proof it works? Google "Marvel Mystery Oil" and read every post on every website that pops up. See what owners, mechanics and engineers in automotive and aviation have to say about MMO. Do your homework if you are going to say something doesn't work!


I know it is inexpensive, that's not what I was asking about. And I don't need to read a pile of anecdotes on the product claiming it does everything from rebuilding your engine to curing cancer... you are providing plenty of those in this thread. However, anecdotes are not proof.

This website also has an additive section where MMO has been discussed in GREAT DETAIL:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=postlist&Board=5&page=1

Feel free to check it out or join the discussion there. You are not the only person on this board with a fondness for MMO.

Quote:

WD40 is not so mythical. Its primary carrying agent is kerosene which would attract water and cause other issues.
MMO makes oil flow easier for another reason. It dissolves and removes fullerenes.


MMO, like WD40, is light. What happens to a heavy oil when you mix in a lighter oil? Exactly.

MANY solvents will dissolve fullerenes....

Comically, there's a lube that claims to use fullerenes to reduce fuel consumption:

http://www.nano.org.uk/news/march2009/latest1817.htm


Quote:
Well if you are tearing down engines in the transportation industry, they get a different kind of use than Soccer Mom cars used in the city and the suburbs.


I'm not. I tear down engines to upgrade them as a hobby, many of them having high miles.

Quote:
If you continually maintain the engines and the driving scenario doesn't cause problems with short trips and prolonged cold weather aggravating carbon build up, MMO may not be needed for that reason. But how do you dissolve the fullerenes in the engine? How do you keep them from plugging up your oil filter and blocking your oil gallery?


I've never had that problem...... And I've worked on engines dating as far back as the 1930's in marine applications. I really think you are misrepresenting the "problem" here.

Quote:
Now that I've answered all your questions


You really didn't answer all my questions. You just spun them around and threw in some big words hoping to confuse me. You make no references to your personal experience with this, even though I specifically asked for it in my first post.

Quote:
and addressed your disagreements above, here is something for YOU to do:

Your assignments in self-education are as follows:

Google "Marvel Mystery Oil" and read several dozen posts on several websites. Try TDI and Maxima. There are plenty to check.
Get a "feel" for what you arguing against because there is a lot of anecdotal evidence readily available that says you need to widen your point of view, if you just look for it.

Look up "fullerenes" so you know and understand what they are and that they develop in an engine because it is the nature of the element carbon to bond with itself.

Also, while you are at it, look up 1,2-dichlorobenzene and 1,4-dichlorobenzene. Take note of the temperature at which they evaporate and also what it is that they are capable of dissolving. Then imagine how those two properties could be used in combination and where that combination would work.

Now you know two of the three principal things that Marvel Mystery Oil can do and why it may be a pretty good thing to add once in while if the usage scenario is one that builds up carbon in the engine.

I'll leave the third thing up to you to find out. When you know what it is, you can tell everyone about it.

So you are assigning me "homework" to look up a pile of anecdotes? Really?

 

[Garak]

Originally Posted By: OVERK1LL
I'm not. I tear down engines to upgrade them as a hobby, many of them having high miles.


I've torn down engines in the transportation industry. I have yet to see any taxi engines that needed MMO, synthetic oil, extra large sumps, or extra oil cooling.

 

[OVERKILL]

Originally Posted By: Garak
Originally Posted By: OVERK1LL
I'm not. I tear down engines to upgrade them as a hobby, many of them having high miles.


I've torn down engines in the transportation industry. I have yet to see any taxi engines that needed MMO, synthetic oil, extra large sumps, or extra oil cooling.


Let's not confound this with silly things like facts Garak

 

[Michael_P]

I know a guy who knows a friend who has a neighbor who uses synthetic. Along with fuel magnets, synthetic car wax, vortex thingies on the air intake, huge outlet mufflers, cold (I mean warm

) air intake and some solid pill like things he tosses in the fuel tank, he has doubled his HP and gas mileage on his 8.0 liter engine, 1 ton truck. I think it's the synthetic. Heck, maybe it's the teflon whatever.

 

[OilGuy2]

Originally Posted By: Garak
Originally Posted By: OVERK1LL
I'm not. I tear down engines to upgrade them as a hobby, many of them having high miles.


I've torn down engines in the transportation industry. I have yet to see any taxi engines that needed MMO, synthetic oil, extra large sumps, or extra oil cooling.


In Saskatchewan Canada, where you live, the average temperatures do not stress lubricants. Also, the longer average drives and the lack of bumper to bumper traffic would assist engines in removing what carbon deposits may form. It is the stop and go, low average trip miles made daily for months on end that contribute to carbon deposits. Also colder seasonal temperatures, along with short trips, contribute to the solidification of paraffin (found in abundance in cheaper Dino oils) with water making sludge in cooler areas such as valve covers and oil pans. Then there is the breakdown of Dino in hot areas of the engine when hotter seasonal ambient temperatures contribute to a heat soaked engine condition.

Short oil change intervals are FORCED by the Dino not being up to the task of the job at hand when the trips are short, the traffic is high, and seasonal temperatures vary from quite cold to quite hot for months at a time.

Why all the "teardowns" anyways? Sounds like some of the maintenance routines (materials, perhaps?) need to be reconsidered. I've known 250,000 mile engines without any mechanical issues that still had compression within specification. I hope you guys aren't tearing engines down in order to clean them up.

 

[OilGuy2]

So you are assigning me "homework" to look up a pile of anecdotes? Really? [/quote]

You can find the other items in encyclopedic and technical publications without difficulty.

With regard to Marvel Mystery Oil, the full formula remains a "proprietary secret" and not every vehicle has a need for its various actions. Therefore, anecdotal evidence provided by actual users, and not the opinions of non-users (like yourself) is a more accurate determinant of its value when the driving scenario creates the need for its properties.

Synthetic Oil, in combination with esters, and molybdenum disulphide, are the "key" to lowest wear and higher fuel mileage. The reduction in friction conserves the energy produced so it available to propel the vehicle, resulting in "less pedal" being needed to attain or maintain speed.

 

[Garak]

Originally Posted By: OilGuy2
In Saskatchewan Canada, where you live, the average temperatures do not stress lubricants. Also, the longer average drives and the lack of bumper to bumper traffic would assist engines in removing what carbon deposits may form. It is the stop and go, low average trip miles made daily for months on end that contribute to carbon deposits. Also colder seasonal temperatures, along with short trips, contribute to the solidification of paraffin (found in abundance in cheaper Dino oils) with water making sludge in cooler areas such as valve covers and oil pans.


First off, we don't live in igloos here. Our summers get to Las Vegas temperatures. And, just because we're not LA or NY doesn't mean we don't have bumper to bumper traffic. When I'm going somewhere, I don't sit in bumper to bumper traffic very long. When a taxi is running around, it is in urban traffic all day. When it's hot out, they idle for AC. When it's cold out, they idle for heat.

As for oil temperature, ambient outside temperatures have an impact, but not a very big one. Our hottest day of the year is about 80 C warmer than our coldest day of the year. The oil temperatures do not differ by 80 C. A 10 C difference is what I've observed.

And you're not going to see a lot of condensation in a taxi engine. I've never once, in millions of miles of running the fleet, seen evidence of condensation in a taxi engine's oil. And there wasn't sludge, either, and dino was used for 6,000 mile OCIs.

Teardowns were done for a couple reasons. The most important one was that the Chevrolets ate cams. When that happens, it's good practice to inspect the rest of the engine if one has time. On occasion, a valve went.

However, using dino all these years, not once did I have to clean sludge. Not once did I ever replace a piston or have to mess with cylinder bore, and not even rings. There was not a single bearing issue, either.

 

[Clevy]

Well since we brought up saskatchewan I can tell you that we hit 40c in the summer and -50 in the winter. For extended periods. So I guess this place could be a proving ground for many things. So oilguy you really don't have a clue. The temps here would stress oil considerably because of the extremes we get. I suggest perhaps investigating the geography of this great land and looking into the average temperatures before commenting that they don't stress oil. I would think this climate would stress oil and engines more than let's say a climate that stays warmer. You can make oil thicker to withstand more heat but how exactly can we make it thinner to flow in the extreme cold. It can only go so thin.

 

[KrisZ]

Originally Posted By: Garak
Originally Posted By: OilGuy2
In Saskatchewan Canada, where you live, the average temperatures do not stress lubricants. Also, the longer average drives and the lack of bumper to bumper traffic would assist engines in removing what carbon deposits may form. It is the stop and go, low average trip miles made daily for months on end that contribute to carbon deposits. Also colder seasonal temperatures, along with short trips, contribute to the solidification of paraffin (found in abundance in cheaper Dino oils) with water making sludge in cooler areas such as valve covers and oil pans.


First off, we don't live in igloos here. Our summers get to Las Vegas temperatures. And, just because we're not LA or NY doesn't mean we don't have bumper to bumper traffic. When I'm going somewhere, I don't sit in bumper to bumper traffic very long. When a taxi is running around, it is in urban traffic all day. When it's hot out, they idle for AC. When it's cold out, they idle for heat.

As for oil temperature, ambient outside temperatures have an impact, but not a very big one. Our hottest day of the year is about 80 C warmer than our coldest day of the year. The oil temperatures do not differ by 80 C. A 10 C difference is what I've observed.

And you're not going to see a lot of condensation in a taxi engine. I've never once, in millions of miles of running the fleet, seen evidence of condensation in a taxi engine's oil. And there wasn't sludge, either, and dino was used for 6,000 mile OCIs.

Teardowns were done for a couple reasons. The most important one was that the Chevrolets ate cams. When that happens, it's good practice to inspect the rest of the engine if one has time. On occasion, a valve went.

However, using dino all these years, not once did I have to clean sludge. Not once did I ever replace a piston or have to mess with cylinder bore, and not even rings. There was not a single bearing issue, either.


Hmm, how is he going to spin this? I know, if you used synthetic with MMO, you wouldn't need teardowns. Poof, another proof that his "reasoning" is right and challenging it with facts and logic is futile.

Also, just to make something clear. I used MMO in the gas and I used synthetics, I still have two or three bottles of MMO left, that I put in the gas tank every once in a while just to use it up. I also track every fill up on the spreadsheet and have the numbers plotted on a graph. You know, the good old fashioned way by calculation, not what the on board display tells me

. There is so much variation between each fill up that it is virtually impossible to tell whether adding MMO or using synthetic has any effect on gas mileage. Little things like running extra/fewer errands or being stuck in traffic few more/less times makes a big difference. Then, if you add variations between the actual volume of gas used for each fill up, remember that they are calibrated (at least in Toronto) to 15C, so even using the same pump will not get rid of the variation, plus all sorts of other variables, like traffic and traffic lights, temperature, etc. and you can see (hopefully) how difficult it is to ACCURATELY measure gas consumption in real world operation.

I look at trends, and the only trend that can be clearly seen on the graph is that the gas mileage starts to improve as weather gets wormer, and as temperatures start to drop the gas mileage suffers. Basically the graph looks like a very wide "U", with the lowest point (or highest when using MPGs) during summer.