fuel economy is a measure of efficiency, additives are snake oil

mndriver

curmudgeon extraordinare
Supporter
Fuel economy is a measure of efficiency. Efficiency of the engine to convert chemical energy into mechanical motion by performing work. A typical engine is only about 78% efficient.
http://www.ehow.com/about_5089284_volumetric-efficiency.html

Modern diesels moved to improve efficiency by adding a turbo charger or a super charger to the engine to increase the air mass charged into the cylinder. More air allows for more fuel to be injected. Theoretically, able to achieve 105-108% efficiency. With modern computer controls, it allows for more efficiency and better fuel mileage.

But to GET all that efficiency, everything MUST work correctly. NO intake leaks, No exhaust leaks, engine compression leaks or fuel system issues.

Valves, injectors, CAC, Gaskets etc. All mechanical items that if they AREN'T right, anything else you do will likely never show whether it was even worth doing the item for in the first place. That would go so far as to include even how the driver disciplines themselves in operating the piece of equipment.

So in the game of fuel mileage, your equipment MUST be 100% to begin with to ensure you can start to even THINK about tweaking.

Modern production engines are sent down the road somewhat castrated. They need to be able to meet emission standards. If they can't they tune them so that they can. That's for the "general population" of operators. Basically, you can call it "drivability."

I'll leave more of that discussion as far as the mechanical stuff to other threads. My point of this posting is to discuss "additives". IMHO, I call them snake oils. And for good reason.

Fuel contamination and fuel system issues are mainly attributed to one of two items; external and internal.

External contaminants are like Water, dirt, chemicals etc. Some of it induced in the case of chemicals. Not all chemicals are good in a diesel fuel system. That's where you have things like a FASS fuel filter system, DAVCO or other spin on fuel water separator system put into place comes into place. My Series 60 Detroit calls for a 7 micron filter to remove the debris from the fuel.

Then you have an internal contamination. This is put into the fuel BY the engine. Oil, Coolant, carbon and asphaltene. Carbon, oil and coolant are all signs of bigger more major issues going on. Namely up around either the injectors or the fuel pumps. And it should NOT be ignored.

Asphaltene though is a bugger on its own. A tar-like substance that the modern engines make that wasn't really heard of in the older mechanical engines. Namely because it's created under heat and pressures that the old systems never saw that we now see in the common rail systems.

The best thing I have found for cleaning injectors IN the engine is this stuff. It's like $8-10 a pint and treats 250 gallons. Nor do you need to use a bunch ALL The time. Maybe once every year depending on how you run your truck.

Cummins Asphaltene conditioner.
http://www.cumminsfiltration.com/html/en/products/fuel/additives/asph_cond.html

Ashpaltene is nasty stuff. It's mainly the stuff that is sticky and gummy like that makes things like injectors NOT work like they are supposed to. And LOTS of people try to sell a product to claim they "clean your injectors." Some of it works, some of it doesn't.

Best way I have found to prevent injector fouling, don't IDLE your truck. All it does is recirculate your fuel when you don't need to. Aphaltene IS a normal by-product of just running your truck. It develops the more you run the fuel through your injectors. The asphaltene seeds itself and then starts to grow in size until it becomes an issue and starts to coat your fuel system from the inside out. The other way I know of to control your asphaltene load in your fuel, run your tanks as low as your dare run them. The lower the better. Get all the crud out of your system and let the filter DO ITS JOB. Partly why I LOVE my davco fuel filter.

This is where I though I was last November. I had a layer of crud inside my right side tank that was causing my fuel filter to plug in as quick as 75 miles.

Turns out, it was an Alge bloom. In November. I thought it was only a warm weather issues. It's not. It's also a cool (into Minnesota December temps even) weather issues as well. I have to flush my system with Emergency 911 for displacing water. Kill'em to kill the algae and Fuel system cleaner to clean the dead algae out of my tank.

But NONE of that could improve or change the physical property of fuel.


Remember what I said about volumetric efficiency up higher. Diesel fuel only has a finite amount of BTU's in it. Stuff like Biodiesel actual has a LOWER BTU content than dino diesel. Making the issue worse. More biodiesel, Less BTU content. Makes it even MORE important to know WHAT you are pumping into your fuel tanks.

super chargers and turbos are used to increase the volumetric efficiency of diesel engine. By using more air and fuel in the same space. You'd have to ADD 20% or more of the diesel BTU's injected into the engine with a wonder chemical with 1/5 the volume of the diesel to make it give you a 14% increase in fuel efficiency to go from 7 to 8 mpg in fuel mileage.
http://generatorjoe.net/html/energy.html
 
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Mike

Well-Known Member
Staff member
That was worthy of its own thread, hope you approve of the title :)
 

mndriver

curmudgeon extraordinare
Supporter
Works for me. I was wondering about it. Hence my prior message to you. I agree sometimes, additives are a needed item, but the majority of time, I just can't see the use. Especially when you understand the physics of what the engines are doing..
 

Duck

Custom title
Supporter
The stuff they call "algea" in diesel fuel tanks is not really algae. I forget what it actually is but it's not an organic material.
 

Mike

Well-Known Member
Staff member
Some people swear by them, others deny any benefit. I used them a few times this winter because I got a little nervous about gelling.

I was planning on testing them this summer to see if I could notice any mpg gains, but too many other things took up my time.
 

Combatdriver69

Well-Known Member
Fuel economy is a measure of efficiency. Efficiency of the engine to convert chemical energy into mechanical motion by performing work. A typical engine is only about 78% efficient.
http://www.ehow.com/about_5089284_volumetric-efficiency.html

Modern diesels moved to improve efficiency by adding a turbo charger or a super charger to the engine to increase the air mass charged into the cylinder. More air allows for more fuel to be injected. Theoretically, able to achieve 105-108% efficiency. With modern computer controls, it allows for more efficiency and better fuel mileage.

But to GET all that efficiency, everything MUST work correctly. NO intake leaks, No exhaust leaks, engine compression leaks or fuel system issues.

Valves, injectors, CAC, Gaskets etc. All mechanical items that if they AREN'T right, anything else you do will likely never show whether it was even worth doing the item for in the first place. That would go so far as to include even how the driver disciplines themselves in operating the piece of equipment.

So in the game of fuel mileage, your equipment MUST be 100% to begin with to ensure you can start to even THINK about tweaking.

Modern production engines are sent down the road somewhat castrated. They need to be able to meet emission standards. If they can't they tune them so that they can. That's for the "general population" of operators. Basically, you can call it "drivability."

I'll leave more of that discussion as far as the mechanical stuff to other threads. My point of this posting is to discuss "additives". IMHO, I call them snake oils. And for good reason.

Fuel contamination and fuel system issues are mainly attributed to one of two items; external and internal.

External contaminants are like Water, dirt, chemicals etc. Some of it induced in the case of chemicals. Not all chemicals are good in a diesel fuel system. That's where you have things like a FASS fuel filter system, DAVCO or other spin on fuel water separator system put into place comes into place. My Series 60 Detroit calls for a 7 micron filter to remove the debris from the fuel.

Then you have an internal contamination. This is put into the fuel BY the engine. Oil, Coolant, carbon and asphaltene. Carbon, oil and coolant are all signs of bigger more major issues going on. Namely up around either the injectors or the fuel pumps. And it should NOT be ignored.

Asphaltene though is a bugger on its own. A tar-like substance that the modern engines make that wasn't really heard of in the older mechanical engines. Namely because it's created under heat and pressures that the old systems never saw that we now see in the common rail systems.

The best thing I have found for cleaning injectors IN the engine is this stuff. It's like $8-10 a pint and treats 250 gallons. Nor do you need to use a bunch ALL The time. Maybe once every year depending on how you run your truck.

Cummins Asphaltene conditioner.
http://www.cumminsfiltration.com/html/en/products/fuel/additives/asph_cond.html

Ashpaltene is nasty stuff. It's mainly the stuff that is sticky and gummy like that makes things like injectors NOT work like they are supposed to. And LOTS of people try to sell a product to claim they "clean your injectors." Some of it works, some of it doesn't.

Best way I have found to prevent injector fouling, don't IDLE your truck. All it does is recirculate your fuel when you don't need to. Aphaltene IS a normal by-product of just running your truck. It develops the more you run the fuel through your injectors. The asphaltene seeds itself and then starts to grow in size until it becomes an issue and starts to coat your fuel system from the inside out. The other way I know of to control your asphaltene load in your fuel, run your tanks as low as your dare run them. The lower the better. Get all the crud out of your system and let the filter DO ITS JOB. Partly why I LOVE my davco fuel filter.

This is where I though I was last November. I had a layer of crud inside my right side tank that was causing my fuel filter to plug in as quick as 75 miles.

Turns out, it was an Alge bloom. In November. I thought it was only a warm weather issues. It's not. It's also a cool (into Minnesota December temps even) weather issues as well. I have to flush my system with Emergency 911 for displacing water. Kill'em to kill the algae and Fuel system cleaner to clean the dead algae out of my tank.

But NONE of that could improve or change the physical property of fuel.


Remember what I said about volumetric efficiency up higher. Diesel fuel only has a finite amount of BTU's in it. Stuff like Biodiesel actual has a LOWER BTU content than dino diesel. Making the issue worse. More biodiesel, Less BTU content. Makes it even MORE important to know WHAT you are pumping into your fuel tanks.

super chargers and turbos are used to increase the volumetric efficiency of diesel engine. By using more air and fuel in the same space. You'd have to ADD 20% or more of the diesel BTU's injected into the engine with a wonder chemical with 1/5 the volume of the diesel to make it give you a 14% increase in fuel efficiency to go from 7 to 8 mpg in fuel mileage.
http://generatorjoe.net/html/energy.html
It does increase the Cetane BTU whatever it's been working for me I've used for 14 months. If it didn't work the oil fields of Canada and Alaska surely wouldn't spend the $$ to help their equip get better MPG's
I've done my research on this product
 

mndriver

curmudgeon extraordinare
Supporter
Then please share that research.

BTU content is but content.

Newton's law of conservation energy states you cannot create nor destroy energy.

And that is exactly what fuel additives are claiming to be able to do.

You get better economy by making your engine work as it should. IE, intake and exhaust are totally intact,engine is working as it should, reducing drag or reducing inefficient operation of the engine by changing operator habits.

There's only so much we can do with drag on current trucks and trailers as designed.

Operator habits can be an easy target.

But you simply can't argue with physics.
 

Duck

Custom title
Supporter
Newton's law of conservation energy states you cannot create nor destroy energy.

And that is exactly what fuel additives are claiming to be able to do.
Um, no. That's not what they're claiming to do.

Piston engines are only something like 30% efficient. That means 70% of the energy in the fuel is converted to heat instead of mechanical energy. These additives claim to make the fuel burn more efficiently so there's more explosion, less heat.

I'm not saying they actually accomplish that, .. just that they're not claiming to have broken the laws of physics.

You get better economy by making your engine work as it should. IE, intake and exhaust are totally intact,engine is working as it should, reducing drag or reducing inefficient operation of the engine by changing operator habits.

There's only so much we can do with drag on current trucks and trailers as designed.
If the additive increases lubricity in the upper cylinders, it will reduce drag & therefore increase efficiency. Whether it'll be a noticeable difference, I have no idea.
Operator habits can be an easy target.
That's where you'll see the biggest improvements.
But you simply can't argue with physics.
You can argue with PEOPLE who don't understand physics though. ;)
I do it all the time. Like when people think wind chill actually lowers the air temperature. :coocoo:
 
Last edited by a moderator:

Combatdriver69

Well-Known Member
Then please share that research.

BTU content is but content.

Newton's law of conservation energy states you cannot create nor destroy energy.

And that is exactly what fuel additives are claiming to be able to do.

You get better economy by making your engine work as it should. IE, intake and exhaust are totally intact,engine is working as it should, reducing drag or reducing inefficient operation of the engine by changing operator habits.

There's only so much we can do with drag on current trucks and trailers as designed.

Operator habits can be an easy target.

But you simply can't argue with physics.
True I get 3 axle alignment every 100K or sooner if I feel a pull or notice anything a miss with my tires.
I run centramatics all tires.
Plus I have air tabs installed
I Check my air pressure regularly
I try to keep all rocks out of my tires as possible.
 

AlexG

Well-Known Member
Um, no. That's not what they're claiming to do.

Piston engines are only something like 30% efficient. That means 70% of the energy in the fuel is converted to heat instead of mechanical energy. These additives claim to make the fuel burn more efficiently so there's more explosion, less heat.

I'm not saying they actually accomplish that, .. just that they're not claiming to have broken the laws of thermodynamics.


If the additive increases lubricity in the upper cylinders, it will reduce drag & therefore increase efficiency. Whether it'll be a noticeable difference, I have no idea.
That's where you'll see the biggest improvements.

You can argue with PEOPLE who don't understand physics though. ;)
I do it all the time. Like when people think wind chill actually lowers the air temperature. :coocoo:
There we go, someone said it.
From my experience when i had my century it would give me mpgs. I would usually get 4.32 mpgs but every Monday i would put a bottle of cetane booster after i fueled up. The read would go up to like 4.38 then the next refuel it would go back to 4.32, i only used it cuz it claim to keep the injectors cleans. I bet if i did the math i wasnt saving the 10 bucks it cost.

But what i found was the when i switched from Donaldson fuel filters to fleetgaurd i got like 4.65. I never cared about fuel economy but i kept an eye on it just for fun.
 

Duck

Custom title
Supporter
There we go, someone said it.
From my experience when i had my century it would give me mpgs. I would usually get 4.32 mpgs but every Monday i would put a bottle of cetane booster after i fueled up. The read would go up to like 4.38 then the next refuel it would go back to 4.32, i only used it cuz it claim to keep the injectors cleans. I bet if i did the math i wasnt saving the 10 bucks it cost.

But what i found was the when i switched from Donaldson fuel filters to fleetgaurd i got like 4.65. I never cared about fuel economy but i kept an eye on it just for fun.
As a company driver I don't give much of a crap about fuel economy but I still find it interesting to see what practices result in better fuel economy.

I used to anyway. That was back when the company had trucks that could possibly be driven with a light foot. Now all they have is the newer junk with the DEF systems and they're so weak & underpowered that if you don't flat-foot it after every shift, you'll never get moving at all. So nowadays when I'm driving their trucks I don't give a crap about fuel economy. And they're phasing out the Kenworths & going with all Volvos with 13 liter Volvo engines and 12 speed autoshifts. I haven't driven one yet except for one 300 mile segment of a trip when I was hitching a ride home after recovering one of their Kenworths. It sucked so bad I don't think I'll ever drive one again. I'll tell 'em to send someone else to go get it, LOL.
 

Combatdriver69

Well-Known Member
As a company driver I don't give much of a crap about fuel economy but I still find it interesting to see what practices result in better fuel economy.

I used to anyway. That was back when the company had trucks that could possibly be driven with a light foot. Now all they have is the newer junk with the DEF systems and they're so weak & underpowered that if you don't flat-foot it after every shift, you'll never get moving at all. So nowadays when I'm driving their trucks I don't give a crap about fuel economy. And they're phasing out the Kenworths & going with all Volvos with 13 liter Volvo engines and 12 speed autoshifts. Ihaven't driven one yet except for one 300 mile segment of a trip when I was hitching a ride home after recovering one of their Kenworths. It sucked so bad I don't think I'll ever drive one again. I'll tell 'em to send someone else to go get it, LOL.
Well it just sounds like your company has them turned downed. I have a 2011 KW T 660 PACCAR MX 13 liter 13 speeds 3.36 and I don't have to flat foot it as you say. You loose most of your MPG's on acceleration, idle time, or over reviving the engine.
 

mndriver

curmudgeon extraordinare
Supporter
@Duck

Don't confuse thermal efficiency with volumetric.

@combat...

Cetane is a measure just like octane of how well fuel will ignite. Unfortunately, as cetane goes up, btu content in fuel goes down. The article I posted above also includes the links for atsm which has the standards for determining cetane rating.

Now...this is where it is snake oil as far as I am concerned.....

You said 1 gallon treats 3940 gallons.........


Think about the rate of dilution on that right there....


That makes a ratio of 3940:1 for some magic potion to suddenly increase your fuel mileage 15% at a truly unknown mix ratio if you are tank mixing......

That means you'd be putting in a half cup of coffer per 120 gal fuel tank. A mere 4 oz of super fluid and you'd be able to save 18 gallons of fuel in a tank.....

That's some super fluid.........
 

Southern Fried

Well-Known Member
Y'all left out the consideration that fuel oils are a blend to begin with.... they already have "additives" in them straight from the refineries..... to compensate for things like atmospheric pressures due to altitudes, temperature differentials, etc, etc, and even assembly differences (why you can have one engine work fine but the one behind it on the assembly line be a total pig).

Stuff is designed/built for "average" usage.

When I was coming up lots of the "old guys" swore by adding a quart of ATF to every second fuel up. They claimed it cleaned the injectors, valves, pistons and suchlike. Dunno if it really did all that but I have seen the inside of engines with and without the "treatment" and the ones "with" had very little carbon so......

Do additives work? Probably yes.... to some degree..... in some applications....

If I had my own truck would I run it? Yup, cheap insurance.
 

Combatdriver69

Well-Known Member
@Duck

Don't confuse thermal efficiency with volumetric.

@combat...

Cetane is a measure just like octane of how well fuel will ignite. Unfortunately, as cetane goes up, btu content in fuel goes down. The article I posted above also includes the links for atsm which has the standards for determining cetane rating.

Now...this is where it is snake oil as far as I am concerned.....

You said 1 gallon treats 3940 gallons.........


Think about the rate of dilution on that right there....


That makes a ratio of 3940:1 for some magic potion to suddenly increase your fuel mileage 15% at a truly unknown mix ratio if you are tank mixing......

That means you'd be putting in a half cup of coffer per 120 gal fuel tank. A mere 4 oz of super fluid and you'd be able to save 18 gallons of fuel in a tank.....

That's some super fluid.........
Well I've seen the results it's working for me. I have a local farmer I gave him some last year to try and it increases his MPG's on his equip 8% he just bought several more gallons to treat his 6000 gallon tank. I see results and you can quote all the info you want but I have experienced so that's what I go by
 

Mike

Well-Known Member
Staff member
Driving for fuel economy simply isn't possible with a neutered down piece of ****. That's what I'm saying. You have to flat-foot it after every shift, unless it's empty or bobtail. It's either that, or you simply do not gain any speed.

The ones I'm referring to have a Cummins ISX 15 liter with the DEF systems. The older ones with just the DPF systems have all been traded off, but in spite of the frequent problems they had, they would at least pull pretty well.

About the only thing you can do for fuel economy with the newer ones is not idle it, and to coast to stops as much as you can without using the wheel or jake brakes.
Plenty of people are driving these, and every other new model engine for great fuel economy.

The power is there, but it is low rpm torque meant to maintain speed and pulling power, not the acceleration that you get from older engines.
 

Mike

Well-Known Member
Staff member
Y'all left out the consideration that fuel oils are a blend to begin with.... they already have "additives" in them straight from the refineries..... to compensate for things like atmospheric pressures due to altitudes, temperature differentials, etc, etc, and even assembly differences (why you can have one engine work fine but the one behind it on the assembly line be a total pig).

Stuff is designed/built for "average" usage.

When I was coming up lots of the "old guys" swore by adding a quart of ATF to every second fuel up. They claimed it cleaned the injectors, valves, pistons and suchlike. Dunno if it really did all that but I have seen the inside of engines with and without the "treatment" and the ones "with" had very little carbon so......

Do additives work? Probably yes.... to some degree..... in some applications....

If I had my own truck would I run it? Yup, cheap insurance.
+1

Probably about the best analysis that can be given about this subject. The amount of a concentrated additive that it takes to make a change to diesel or other petroleum products can be very small.
 

Copperhead

Well-Known Member
There are additives that can help, but primarily to keep things in working order. I dose my tanks once each month with FPPF Killem to stop any potential algae growth from going on. I dose the fuel occasionally with an injector and fuel system cleaner to eliminate any varnish or deposit buildup in the injectors. I don't worry about lubricity, since most of the fuel I put in has some biodiesel in it, and that raises the lubricity to higher levels than any drop in additive will do. My pre-egr Detroit does not "cook" the fuel nearly as bad as my previous ISX did, so it seems the asphaltane issue is non existent in my case.

One area that most fuels can use help is Cetane. The combustion quality of the fuel. Europe has higher cetane number requirements than we do in the U.S. The refineries are only going to raise cetane to minimum numbers that the feds tell them, which if you take a look at engine manufacturer papers on this, is not always up the level the OEM's recommend. A cetane improver may or may not help that much, but it is not a bad idea.

Now to all of this, I get a very good diesel fuel additive from my oil supplier, Schaeffer, at a very reasonable cost. A 5 gallon pail is about $164, is delivered free to my door, and one oz treats 15 gallons of fuel. So I am treating my fuel for under 2 cents a gallon. A far better deal than most anything that one could buy off the shelf. And it complements the Schaeffer oil I am using in the engine.
 

Injun

Rabid Squaw
Staff member
Supporter
There are additives that can help, but primarily to keep things in working order. I dose my tanks once each month with FPPF Killem to stop any potential algae growth from going on.
These guys might be trying to sell something, but whatever. This article is spot-on. This "algae" is NOT living material that can "grow."

http://engines1.novosolutions.net/default.asp?id=275

....the black slimy material frequently seen
in their fuel filter elements, and found in the bottoms of their fuel tanks. It is known by many names e.g. algae, mud,
sludge, dirt, BS&W, and many other unsavory sounding terms – all of which are misnomers. Many people think this
material is some sort of microbe, thus in the marine industry, it is most commonly called “algae”.
...the cause of the so called “algae” is simply the result of ageing fuel, which can occur in as little as 60-90 days,
and depending on the cleanliness, and maintenance of the tanks in which it is kept, possibly even sooner.
 

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