WOW..I always thought K & N filters were highly regarded, I guess not everybody feels the love for them.
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K&N filters do they increase gas mileage?????????
- Thread starter dbvettez061
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Read some UOA's and you will 'lose the love'
so, for strickly a mileage gain on a f.i. car, can you bottle-neck the incoming air so less air=less gas?
Originally Posted By: daves66nova
so, for strickly a mileage gain on a f.i. car, can you bottle-neck the incoming air so less air=less gas?
That's all the gas pedal does is let more/less air through the intake. You could get the same effect as what you suggest by putting a block of wood underneath the pedal. Of course either of the two would mean a reduction in max power. I'd just be worried that limiting my car could put me in danger. I've seen a lot more situations where going faster is the best way to avoid impending doom versus slamming on the brakes.
calvin
so, for strickly a mileage gain on a f.i. car, can you bottle-neck the incoming air so less air=less gas?
That's all the gas pedal does is let more/less air through the intake. You could get the same effect as what you suggest by putting a block of wood underneath the pedal. Of course either of the two would mean a reduction in max power. I'd just be worried that limiting my car could put me in danger. I've seen a lot more situations where going faster is the best way to avoid impending doom versus slamming on the brakes.
calvin
The job of the throttle is to restrict the air entering the engine at every point except floorboarded. A dirty, restrictive air filter does somewhat the same thing.
The mass airflow sensor measures the precise amount of air entering the engine and helps determine exactly how much fuel to inject into the engine for best combustion, clean exhaust, best mileage, etc.
The only ways a dirty air filter can do harm is (1) if dirt works its way through, or (2) limits top end power. The dirty air filter makes zero effect on fuel mileage or drivability below top end.
The mass airflow sensor measures the precise amount of air entering the engine and helps determine exactly how much fuel to inject into the engine for best combustion, clean exhaust, best mileage, etc.
The only ways a dirty air filter can do harm is (1) if dirt works its way through, or (2) limits top end power. The dirty air filter makes zero effect on fuel mileage or drivability below top end.
Originally Posted By: Sworkhard
Although most modern cars have no appreciable fuel economy difference with high flow filter/intake, eg, my 03 accord, my old 04 cavalier 3spd auto had a 10% increase in fuel economy between 85 and 115 km/h (95% highway) ~33mpg to ~37mpg The combination of the warmer air (more efficient combustion) and less restriction made a pretty significant difference. I took a lot of long trips with the car so the $30 investment i spent on my short ram filter (not a k&n) (after market filter on stock pipe) paid for itself in a couple of months.
How the [censored] does less restriction on a non-carbureted car give you better mileage. Does this stuff ever end?
Although most modern cars have no appreciable fuel economy difference with high flow filter/intake, eg, my 03 accord, my old 04 cavalier 3spd auto had a 10% increase in fuel economy between 85 and 115 km/h (95% highway) ~33mpg to ~37mpg The combination of the warmer air (more efficient combustion) and less restriction made a pretty significant difference. I took a lot of long trips with the car so the $30 investment i spent on my short ram filter (not a k&n) (after market filter on stock pipe) paid for itself in a couple of months.
How the [censored] does less restriction on a non-carbureted car give you better mileage. Does this stuff ever end?
Originally Posted By: Ken2
The job of the throttle is to restrict the air entering the engine at every point except floorboarded. A dirty, restrictive air filter does somewhat the same thing.
The mass airflow sensor measures the precise amount of air entering the engine and helps determine exactly how much fuel to inject into the engine for best combustion, clean exhaust, best mileage, etc.
The only ways a dirty air filter can do harm is (1) if dirt works its way through, or (2) limits top end power. The dirty air filter makes zero effect on fuel mileage or drivability below top end.
IF A DIRTY AIR FILTER IS ONE WAY TO HELP FUEL MILEAGE, WHY DOES THE MANUAFCTURER STIPLULATE THAT IT SHOULD BE CHANGED AT PRESCIBED INTERVALS.
YOU SAYING IF YOU NEVR TRAMP THE CAR near the top end YOU DON'T NEED TO CHANGE IT.
I THOUGHT A DIRTY AIR FILTER MAKES YOUR CAR RUN RICH. THIS IS NEWS TO ME. THIS IS THE OPPOSITE OF WHAT I HAVE READ.
DIRTY AIR FILTERS can also cause other systems to run ineffectively, such as your emissions control system, which regulates the car's air-fuel mixture.
A dirty air filter can also cause your spark plugs, which ignite the fuel in the combustion chambers, to foul, as there will be too much fuel without enough air; if your spark plugs foul, you may have problems keeping your car running.
The job of the throttle is to restrict the air entering the engine at every point except floorboarded. A dirty, restrictive air filter does somewhat the same thing.
The mass airflow sensor measures the precise amount of air entering the engine and helps determine exactly how much fuel to inject into the engine for best combustion, clean exhaust, best mileage, etc.
The only ways a dirty air filter can do harm is (1) if dirt works its way through, or (2) limits top end power. The dirty air filter makes zero effect on fuel mileage or drivability below top end.
IF A DIRTY AIR FILTER IS ONE WAY TO HELP FUEL MILEAGE, WHY DOES THE MANUAFCTURER STIPLULATE THAT IT SHOULD BE CHANGED AT PRESCIBED INTERVALS.
YOU SAYING IF YOU NEVR TRAMP THE CAR near the top end YOU DON'T NEED TO CHANGE IT.
I THOUGHT A DIRTY AIR FILTER MAKES YOUR CAR RUN RICH. THIS IS NEWS TO ME. THIS IS THE OPPOSITE OF WHAT I HAVE READ.
DIRTY AIR FILTERS can also cause other systems to run ineffectively, such as your emissions control system, which regulates the car's air-fuel mixture.
A dirty air filter can also cause your spark plugs, which ignite the fuel in the combustion chambers, to foul, as there will be too much fuel without enough air; if your spark plugs foul, you may have problems keeping your car running.
Originally Posted By: virginoil
IF A DIRTY AIR FILTER IS ONE WAY TO HELP FUEL MILEAGE, WHY DOES THE MANUAFCTURER STIPLULATE THAT IT SHOULD BE CHANGED AT PRESCIBED INTERVALS.
YOU SAYING IF YOU NEVR TRAMP THE CAR near the top end YOU DON'T NEED TO CHANGE IT.
I THOUGHT A DIRTY AIR FILTER MAKES YOUR CAR RUN RICH. THIS IS NEWS TO ME. THIS IS THE OPPOSITE OF WHAT I HAVE READ.
DIRTY AIR FILTERS can also cause other systems to run ineffectively, such as your emissions control system, which regulates the car's air-fuel mixture.
A dirty air filter can also cause your spark plugs, which ignite the fuel in the combustion chambers, to foul, as there will be too much fuel without enough air; if your spark plugs foul, you may have problems keeping your car running.
Don't shout if you don't know what you are talking about; it only makes you look more foolish. Explain how a dirty air filter causes an over-rich condition and I'll post an all-caps apology. Nobody here is saying that a dirty air filter is a good thing. What we ARE saying is that a dirty air filter won't have a negative impact on fuel mileage.
And just to make sure we are on the same page, this applies specifically to fuel injected cars. For US market cars this means pretty much anything sold in the last 15-20 years.
Calvin
IF A DIRTY AIR FILTER IS ONE WAY TO HELP FUEL MILEAGE, WHY DOES THE MANUAFCTURER STIPLULATE THAT IT SHOULD BE CHANGED AT PRESCIBED INTERVALS.
YOU SAYING IF YOU NEVR TRAMP THE CAR near the top end YOU DON'T NEED TO CHANGE IT.
I THOUGHT A DIRTY AIR FILTER MAKES YOUR CAR RUN RICH. THIS IS NEWS TO ME. THIS IS THE OPPOSITE OF WHAT I HAVE READ.
DIRTY AIR FILTERS can also cause other systems to run ineffectively, such as your emissions control system, which regulates the car's air-fuel mixture.
A dirty air filter can also cause your spark plugs, which ignite the fuel in the combustion chambers, to foul, as there will be too much fuel without enough air; if your spark plugs foul, you may have problems keeping your car running.
Don't shout if you don't know what you are talking about; it only makes you look more foolish. Explain how a dirty air filter causes an over-rich condition and I'll post an all-caps apology. Nobody here is saying that a dirty air filter is a good thing. What we ARE saying is that a dirty air filter won't have a negative impact on fuel mileage.
And just to make sure we are on the same page, this applies specifically to fuel injected cars. For US market cars this means pretty much anything sold in the last 15-20 years.
Calvin
Who's shouting ?? Reread second half or my post.
Remember there are new members on this site and may take some postings literally.
Anyway my understanding is the the engine doesn't inject that much more fuel into the combustion chamber in the case of insufficient charge (air). Doing so would probably drown the spark plugs, so the computer reduces injector flow slightly and burns less potent to appropriately match the available charge air, reducing output.
The injector rate doesn't scale back 1:1 to the amount of air (reducing fluid rates through the same diameter nozzle is too coarse to have that kind of accuracy) so you end up with some more fuel than the usual ratio.
This has a direct influence on fuel economy because you need to press the pedal harder for the engine to do the same work and you use more fuel in the process.
I trust this helps.
If the above information is incorrect please explain how a dirty filter has no affect on fuel injected vehicles.
Remember there are new members on this site and may take some postings literally.
Anyway my understanding is the the engine doesn't inject that much more fuel into the combustion chamber in the case of insufficient charge (air). Doing so would probably drown the spark plugs, so the computer reduces injector flow slightly and burns less potent to appropriately match the available charge air, reducing output.
The injector rate doesn't scale back 1:1 to the amount of air (reducing fluid rates through the same diameter nozzle is too coarse to have that kind of accuracy) so you end up with some more fuel than the usual ratio.
This has a direct influence on fuel economy because you need to press the pedal harder for the engine to do the same work and you use more fuel in the process.
I trust this helps.
If the above information is incorrect please explain how a dirty filter has no affect on fuel injected vehicles.
Last edited:
POSTING LIKE THIS IS SHOUTING! YOU KIDS GET OFF MY LAWN!
Once the ECU goes to closed loop fuel flow can be anything: ZERO to FULL. Closed loop means the ECU checks to see if the 02 sensor, sees a lean condition and lengthens the injector pulse or sees a rich condition and shortens the injector pulse. There is no minimum injector pulse width; in fact under deceleration the ECU will cut fuel completely over a certain RPM (1500 on Ford EEC-IV).
Google computerized engine management for more. It's a big topic. The short version is that yes the ECU is both able and willing to trim fuel to match incoming air volume. That's its job.
calvin
Once the ECU goes to closed loop fuel flow can be anything: ZERO to FULL. Closed loop means the ECU checks to see if the 02 sensor, sees a lean condition and lengthens the injector pulse or sees a rich condition and shortens the injector pulse. There is no minimum injector pulse width; in fact under deceleration the ECU will cut fuel completely over a certain RPM (1500 on Ford EEC-IV).
Google computerized engine management for more. It's a big topic. The short version is that yes the ECU is both able and willing to trim fuel to match incoming air volume. That's its job.
calvin
I am not sure you read my post.
The accuracy of the fuel injection is not as precise as you suggest to match the reduction in air flow. The engine management system can only compensate so much within the limits programmed into to work with such as dirty air filters.
I am not sure what you consider a dirty air filter to be.
Good idea Google dirty air filter and affect on fuel injected vehicles.
The accuracy of the fuel injection is not as precise as you suggest to match the reduction in air flow. The engine management system can only compensate so much within the limits programmed into to work with such as dirty air filters.
I am not sure what you consider a dirty air filter to be.
Good idea Google dirty air filter and affect on fuel injected vehicles.
Uh, i just tried googling like you suggested (Google dirty air filter and affect on fuel injected vehicles),
and the top hits were all the opposite of your argument.
The links say that the dirty filter does not decrease MPG significantly.
Please post links to back up your argument to show that at least someone else agrees with you!
1st hit:
http://www.ls1tech.com/forums/advanced-e...ct-fiction.html
2nd hit didn't have any result:
3rd hit didn't have it spelled out
4th hit:
http://www.carrentals.co.uk/blog/fuel-economy-facts-and-myths.html
Saying it no longer applies
6th hit:
http://www.chicagotribune.com/business/a...,2632064.column
saying it no longer applies
and the top hits were all the opposite of your argument.
The links say that the dirty filter does not decrease MPG significantly.
Please post links to back up your argument to show that at least someone else agrees with you!
1st hit:
http://www.ls1tech.com/forums/advanced-e...ct-fiction.html
2nd hit didn't have any result:
3rd hit didn't have it spelled out
4th hit:
http://www.carrentals.co.uk/blog/fuel-economy-facts-and-myths.html
Saying it no longer applies
6th hit:
http://www.chicagotribune.com/business/a...,2632064.column
saying it no longer applies
Last edited:
This from the about.com forums in response to this very question:
Quote:
From: DavidVespremi
Date: 5/19/06
[Note from the Guide: David Vespremi of K&N Filters posted the following in response to several comments on a blog post (http://cars.about.com/b/a/216781.htm). Because of the length and detail of his reply, I have moved it here to the forum. David writes:]
I'd like to make myself available for questions and comments on this article. I am the Brand Marketing Director at K&N Engineering, Inc. I am also an automotive enthusiast and published automotive author ("Car Hacks and Mods for Dummies, Yahoo!, and TechTV included)
As such, I can help address some of these questions and concerns as both a knowledgeable enthusiast who has used K&N on various project cars well before I worked for the company, and now most recently, as a representative of K&N.
I am pleased to have been asked to contribute to this dialogue and appreciate the interest in K&N's products. I am further grateful to Aaron for taking the opportunity to provide his readers with objective feedback - be it good or bad - about our products. At K&N, we are proud of the fact that we make the World's Best air filters and intake systems - manufactured in Riverside, California for over 37 years by enthusiasts. To date, over 15 million K&N air filter are in active use worldwide and K&N is one of the few, if not only, companies with a full ISO/SAE filtration lab on site that allows us to continually benchmark our products in every step of the development process. This includes the "three legged stool" of criteria by which we measure our filters’ performance: (1) filtration - the ability to prevent harmful contaminants and particulate matter from getting into the engine (2) flow - the ability to get air to the engine and (3) dirt retention - the ability to perform these over the longest service life possible without a degradation in performance. It is in achieving the “sweet spot” between these three that makes a K&N a K&N.
While it is true that there are filters that stop more particulates than K&N, and that there are those that flow more air, as there those that retain more dirt before degrading in performance, it is K&N’s mission to excel not in any one category – but as a compromise of all three – and to do this with a filter that has a service life for the entire life of your car.
I should further point out that K&N makes no claims that our products improve fuel efficiency. Even the EPAs mandated numbers for OEMs are just estimates, so any estimated improvements on what is itself an estimate is a bit of reach. What we can conclusively say is that under a Department of Energy Report, a clogged air filter can negatively impact fuel economy by up to 10% and that there is a relatively high number of vehicles on the road using paper filters past a point in which fuel mileage is likely being impacted. By using a K&N (or any new filter) that fuel mileage can be restored. The critical difference and primary point of appeal for a K&N Lifetime filter over the disposable variety is that unlike a paper filter, a K&N Lifetime filter never needs to be replaced. As such, the money and hassle you save with K&N as compared to continually buying and replacing paper filters can be avoided. Further, because over 100 million disposable air filters and their associated packaging end up in landfills in the U.S. alone each year, K&N helps reduce the waste associated with the manufacture, transport, and use of these disposable products.
To address the question of why an OEM manufacturer would not be inclined to equip cars with K&N from the factory, one has to look at the business model behind building, selling, and servicing cars. Why do many car manufacturers now offer 10 year 100k warranties? The reason is simple. The cars are well built enough to last that long, but by keeping customers coming back to dealerships for consumables, which includes everything from brake pads and rotors, to spark plugs, to oil changes – and yes – filter changes, the manufacture can build into the target price of every car sold a profit center to subsidize the price of the car.
It is no different from how before the days of bagless vacuum cleaners, a vacuum cleaner would be sold with very little profit margin since the bags themselves would need to be continually repurchased, or why coffee machines were once sold with paper filters specific to the shape and size of that machine before the standard switched to lifetime metal filters. It is a form of planned obsolescence, and one that is against the core philosophy of how K&N engineers its products.
It is clear that paper automotive filters work are a profit center pure and simple. As it is now, K&N is a large global company selling millions of filters a year. Think of how many more a company like ours could sell if we sold more than one per vehicle. However, our value proposition to the consumer is very different and consumers know that while our filters cost a bit more up front, they have the peace of mind from knowing that they are getting the very best for their cars.
To support this, K&N has, of course, been use in Motorsports for many years. This includes Indy Car – every car that crosses the finish line at next week’s Indy 500 will be using a K&N - Champ Car, NHRA, WRC, NASCAR, Baja 500 and 1000, all the way down to the most obscure grassroots forms of motorsports. For those inclined to think that a K&N does not stop dirt, ask a Baja racer some time why they don’t simply elect to use paper filters? Obviously, they must be concerned about the fine silt and dirt getting into their engines in the 1,000 mile desert race.
However, I am not here to extol the performance benefits of a factory replacement filter. Yes, it flows more air than a paper filter - those who have seen K&N's air flow demonstrators (the ones that use the ping pong ball) in retail environments know this to be true. But because it flows more air, or because light is visible through the pleats, doesn't mean that a K&N doesn't excel under SAE/ISO tests under our three-legged stool criteria.
The reason for this is simple, K&N works on an entirely different physics principle than a paper filter. You see, a paper filter stops dirt by presenting a barrier full of pores that fill up with dirt as it accumulates on the filter’s surface. The fewer unclogged pores remain available, the less air the filter is able to pass through to the engine. This is called surface loading. A K&N filter depth loads, meaning that the particulates are held in suspension by a tacking agent. Since the contaminant particles essentially becomes a magnet for other particles, the particles build up on each other into bigger clumps and the air continues to flow around them through the grid matrix weave of the cotton fibers. This is called depth loading.
For those that want performance – a guaranteed increase in horsepower that you can actually feel – K&N offers our performance intake systems. These are significantly more expensive than the Lifetime replacement filters, but their quality and performance are second to none. While our Lifetime filters do outflow paper filters, it is only after eliminating the maze of factory baffles, chambers and plumbing that our Intake Systems provide that an uncompromised increase in performance can be released.
I’ll cut this short for now, but I am happy to answer questions here so please feel free to fire away.
Thanks,
David Vespremi
K&N Brand Marketing Director
Quote:
From: DavidVespremi
Date: 5/19/06
[Note from the Guide: David Vespremi of K&N Filters posted the following in response to several comments on a blog post (http://cars.about.com/b/a/216781.htm). Because of the length and detail of his reply, I have moved it here to the forum. David writes:]
I'd like to make myself available for questions and comments on this article. I am the Brand Marketing Director at K&N Engineering, Inc. I am also an automotive enthusiast and published automotive author ("Car Hacks and Mods for Dummies, Yahoo!, and TechTV included)
As such, I can help address some of these questions and concerns as both a knowledgeable enthusiast who has used K&N on various project cars well before I worked for the company, and now most recently, as a representative of K&N.
I am pleased to have been asked to contribute to this dialogue and appreciate the interest in K&N's products. I am further grateful to Aaron for taking the opportunity to provide his readers with objective feedback - be it good or bad - about our products. At K&N, we are proud of the fact that we make the World's Best air filters and intake systems - manufactured in Riverside, California for over 37 years by enthusiasts. To date, over 15 million K&N air filter are in active use worldwide and K&N is one of the few, if not only, companies with a full ISO/SAE filtration lab on site that allows us to continually benchmark our products in every step of the development process. This includes the "three legged stool" of criteria by which we measure our filters’ performance: (1) filtration - the ability to prevent harmful contaminants and particulate matter from getting into the engine (2) flow - the ability to get air to the engine and (3) dirt retention - the ability to perform these over the longest service life possible without a degradation in performance. It is in achieving the “sweet spot” between these three that makes a K&N a K&N.
While it is true that there are filters that stop more particulates than K&N, and that there are those that flow more air, as there those that retain more dirt before degrading in performance, it is K&N’s mission to excel not in any one category – but as a compromise of all three – and to do this with a filter that has a service life for the entire life of your car.
I should further point out that K&N makes no claims that our products improve fuel efficiency. Even the EPAs mandated numbers for OEMs are just estimates, so any estimated improvements on what is itself an estimate is a bit of reach. What we can conclusively say is that under a Department of Energy Report, a clogged air filter can negatively impact fuel economy by up to 10% and that there is a relatively high number of vehicles on the road using paper filters past a point in which fuel mileage is likely being impacted. By using a K&N (or any new filter) that fuel mileage can be restored. The critical difference and primary point of appeal for a K&N Lifetime filter over the disposable variety is that unlike a paper filter, a K&N Lifetime filter never needs to be replaced. As such, the money and hassle you save with K&N as compared to continually buying and replacing paper filters can be avoided. Further, because over 100 million disposable air filters and their associated packaging end up in landfills in the U.S. alone each year, K&N helps reduce the waste associated with the manufacture, transport, and use of these disposable products.
To address the question of why an OEM manufacturer would not be inclined to equip cars with K&N from the factory, one has to look at the business model behind building, selling, and servicing cars. Why do many car manufacturers now offer 10 year 100k warranties? The reason is simple. The cars are well built enough to last that long, but by keeping customers coming back to dealerships for consumables, which includes everything from brake pads and rotors, to spark plugs, to oil changes – and yes – filter changes, the manufacture can build into the target price of every car sold a profit center to subsidize the price of the car.
It is no different from how before the days of bagless vacuum cleaners, a vacuum cleaner would be sold with very little profit margin since the bags themselves would need to be continually repurchased, or why coffee machines were once sold with paper filters specific to the shape and size of that machine before the standard switched to lifetime metal filters. It is a form of planned obsolescence, and one that is against the core philosophy of how K&N engineers its products.
It is clear that paper automotive filters work are a profit center pure and simple. As it is now, K&N is a large global company selling millions of filters a year. Think of how many more a company like ours could sell if we sold more than one per vehicle. However, our value proposition to the consumer is very different and consumers know that while our filters cost a bit more up front, they have the peace of mind from knowing that they are getting the very best for their cars.
To support this, K&N has, of course, been use in Motorsports for many years. This includes Indy Car – every car that crosses the finish line at next week’s Indy 500 will be using a K&N - Champ Car, NHRA, WRC, NASCAR, Baja 500 and 1000, all the way down to the most obscure grassroots forms of motorsports. For those inclined to think that a K&N does not stop dirt, ask a Baja racer some time why they don’t simply elect to use paper filters? Obviously, they must be concerned about the fine silt and dirt getting into their engines in the 1,000 mile desert race.
However, I am not here to extol the performance benefits of a factory replacement filter. Yes, it flows more air than a paper filter - those who have seen K&N's air flow demonstrators (the ones that use the ping pong ball) in retail environments know this to be true. But because it flows more air, or because light is visible through the pleats, doesn't mean that a K&N doesn't excel under SAE/ISO tests under our three-legged stool criteria.
The reason for this is simple, K&N works on an entirely different physics principle than a paper filter. You see, a paper filter stops dirt by presenting a barrier full of pores that fill up with dirt as it accumulates on the filter’s surface. The fewer unclogged pores remain available, the less air the filter is able to pass through to the engine. This is called surface loading. A K&N filter depth loads, meaning that the particulates are held in suspension by a tacking agent. Since the contaminant particles essentially becomes a magnet for other particles, the particles build up on each other into bigger clumps and the air continues to flow around them through the grid matrix weave of the cotton fibers. This is called depth loading.
For those that want performance – a guaranteed increase in horsepower that you can actually feel – K&N offers our performance intake systems. These are significantly more expensive than the Lifetime replacement filters, but their quality and performance are second to none. While our Lifetime filters do outflow paper filters, it is only after eliminating the maze of factory baffles, chambers and plumbing that our Intake Systems provide that an uncompromised increase in performance can be released.
I’ll cut this short for now, but I am happy to answer questions here so please feel free to fire away.
Thanks,
David Vespremi
K&N Brand Marketing Director
Originally Posted By: virginoil
I am not sure you read my post.
The accuracy of the fuel injection is not as precise as you suggest to match the reduction in air flow. The engine management system can only compensate so much within the limits programmed into to work with such as dirty air filters.
I am not sure what you consider a dirty air filter to be.
Good idea Google dirty air filter and affect on fuel injected vehicles.
You are completely off base.
Explain to me how a dirty air filter restricting airflow is any different than the throttle blade restricting airflow.
A mass air car meters incoming air. If the filter is dirty, it sees less air, the same as it does with a partially closed throttle. What's so hard to understand about that?
A speed density car sees more vaccum in the intake manifold. Again, same result as a partially closed throttle.
To check the calculations of the computer after the fact is the 02 sensor and it will make necessary adjustments if needed.
The fuel metering IS that precise. Again, all a dirty filter hurts is performance. Air fuel ratio remains constant.
On an old carbureted car, it will go rich due to the extra vacuum.
I believe all Domestics had to be fuel injected in '87 or '88.
I am not sure you read my post.
The accuracy of the fuel injection is not as precise as you suggest to match the reduction in air flow. The engine management system can only compensate so much within the limits programmed into to work with such as dirty air filters.
I am not sure what you consider a dirty air filter to be.
Good idea Google dirty air filter and affect on fuel injected vehicles.
You are completely off base.
Explain to me how a dirty air filter restricting airflow is any different than the throttle blade restricting airflow.
A mass air car meters incoming air. If the filter is dirty, it sees less air, the same as it does with a partially closed throttle. What's so hard to understand about that?
A speed density car sees more vaccum in the intake manifold. Again, same result as a partially closed throttle.
To check the calculations of the computer after the fact is the 02 sensor and it will make necessary adjustments if needed.
The fuel metering IS that precise. Again, all a dirty filter hurts is performance. Air fuel ratio remains constant.
On an old carbureted car, it will go rich due to the extra vacuum.
I believe all Domestics had to be fuel injected in '87 or '88.
Believe what you will. If you have ears to hear with.
http://autospeed.com/cms/A_2597/printArticle.html
http://forums.bit-tech.net/showthread.php?t=157514
http://www.unixnerd.demon.co.uk/motronic.html
http://autospeed.com/cms/A_2597/printArticle.html
http://forums.bit-tech.net/showthread.php?t=157514
http://www.unixnerd.demon.co.uk/motronic.html
Last edited:
Read whole article below conclusion is that is is a subject of debate only, not proof of what ypu claim.
1st hit:
http://www.ls1tech.com/forums/advanced-e...ct-fiction.html
Article below shows no proof, just statements. No different to my point of view. I haven't found an Owners Manual or service repair manual for modern vehciles promoting what you are suggesting as acceptable practice.
4th hit:
http://www.carrentals.co.uk/blog/fuel-economy-facts-and-myths.html
Saying it no longer applies
6th hit:
http://www.chicagotribune.com/business/a...,2632064.column
1st hit:
http://www.ls1tech.com/forums/advanced-e...ct-fiction.html
Article below shows no proof, just statements. No different to my point of view. I haven't found an Owners Manual or service repair manual for modern vehciles promoting what you are suggesting as acceptable practice.
4th hit:
http://www.carrentals.co.uk/blog/fuel-economy-facts-and-myths.html
Saying it no longer applies
6th hit:
http://www.chicagotribune.com/business/a...,2632064.column
The articles that I linked aren't proof, they are just following up on your suggestion to google the air filters and MPG, where and the top hits disagreed with you and none of the top hits that I saw agreed.
I saw your links, but I bet you had to actually dig down to find them.
The article that I would like to exhibit as proof is the Consumer Reports test from this summer linked previously where they actually tested a car.
As an correlary, I claim that all the misinformation and other articles you may cite are all out of date. They all come back to the same DoE report (fueleconomy.gov). But really, as I stated before, this cites only a 1981 French study, which I hope we can all agree is no longer relevant.
Your best article is from that automotive DIY magazine. But it is dated from 2005, and they don't say they tested real cars, I bet they just brought together data from other sources and likely just pulled from the same DoE recommendation, which goes back to the outdated 1981 french study..
Even your BMW link, if you look closely they say is for a really wide range of cars (it says 1977-1994). Again, since changing a filter is a no-brainer, I belive they just dumb down the chart, so they don't have to explain the difference between a FI car and an older dumber car so they just throw in change the air filter even if it might not apply to a new car.
Your last link is again from an online forum, who we shouldn't give much credit to.
Please show me a link that has something where they actually tested a car. At a minimum it should state what car they tested (in the CR test, they tested a Camry, and has a date from 2008).
Finally, don't set up a straw man argument. No one is saying don't change the air filter, I agree it is good proper maintenance for your car and you should do it. We're just saying stop spreading the myth that a dirty air filter will affect MPG in a modern car.
And going back to the OP of this thread, the point is don't think that extra air to your car(via aftermarket filter) will give you extra MPG. Even K&N directly says so. What you are looking for with this mod is that it may give you some extra hp (so they claim).
I saw your links, but I bet you had to actually dig down to find them.
The article that I would like to exhibit as proof is the Consumer Reports test from this summer linked previously where they actually tested a car.
As an correlary, I claim that all the misinformation and other articles you may cite are all out of date. They all come back to the same DoE report (fueleconomy.gov). But really, as I stated before, this cites only a 1981 French study, which I hope we can all agree is no longer relevant.
Your best article is from that automotive DIY magazine. But it is dated from 2005, and they don't say they tested real cars, I bet they just brought together data from other sources and likely just pulled from the same DoE recommendation, which goes back to the outdated 1981 french study..
Even your BMW link, if you look closely they say is for a really wide range of cars (it says 1977-1994). Again, since changing a filter is a no-brainer, I belive they just dumb down the chart, so they don't have to explain the difference between a FI car and an older dumber car so they just throw in change the air filter even if it might not apply to a new car.
Your last link is again from an online forum, who we shouldn't give much credit to.
Please show me a link that has something where they actually tested a car. At a minimum it should state what car they tested (in the CR test, they tested a Camry, and has a date from 2008).
Finally, don't set up a straw man argument. No one is saying don't change the air filter, I agree it is good proper maintenance for your car and you should do it. We're just saying stop spreading the myth that a dirty air filter will affect MPG in a modern car.
And going back to the OP of this thread, the point is don't think that extra air to your car(via aftermarket filter) will give you extra MPG. Even K&N directly says so. What you are looking for with this mod is that it may give you some extra hp (so they claim).
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My arguments are more no straw like than the dirty air filters campaign discussed. Your right dig down, the links posted in support of dirty air filters are no more credible than mine IMO.
You own testimony above lays to claim that can refute information based on what you bet and believe.
Dirty air filter will affect MPG in a modern car. This is not a myth IMO. Re read the posts the information is there.
Anyway it is unlikely we will reach agreement on the subject so I am signing off this one for now.
I know what works and doesn't work for me.
You own testimony above lays to claim that can refute information based on what you bet and believe.
Dirty air filter will affect MPG in a modern car. This is not a myth IMO. Re read the posts the information is there.
Anyway it is unlikely we will reach agreement on the subject so I am signing off this one for now.
I know what works and doesn't work for me.
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Originally Posted By: virginoil
My arguments are more no straw like than the dirty air filters campaign discussed. Your right dig down, the links posted in support of dirty air filters are no more credible than mine IMO.
You own testimony above lays to claim that can refute information based on what you bet and believe.
Dirty air filter will affect MPG in a modern car. This is not a myth IMO. Re read the posts the information is there.
Anyway it is unlikely we will reach agreement on the subject so I am signing off this one for now.
I know what works and doesn't work for me.
This is like arguing the sky is green.
If you had any understanding of how fuel injection or even an engine for that mattter works, you would understand that you can't get better mileage from a K&N or worse mileage from a dirty filter on a modern fuel injected car.
Again, you ignore the point "A dirty filter is no different than a partially closed throttlebody"
As soon as you understand this, you will understand why you're wrong.
My arguments are more no straw like than the dirty air filters campaign discussed. Your right dig down, the links posted in support of dirty air filters are no more credible than mine IMO.
You own testimony above lays to claim that can refute information based on what you bet and believe.
Dirty air filter will affect MPG in a modern car. This is not a myth IMO. Re read the posts the information is there.
Anyway it is unlikely we will reach agreement on the subject so I am signing off this one for now.
I know what works and doesn't work for me.
This is like arguing the sky is green.
If you had any understanding of how fuel injection or even an engine for that mattter works, you would understand that you can't get better mileage from a K&N or worse mileage from a dirty filter on a modern fuel injected car.
Again, you ignore the point "A dirty filter is no different than a partially closed throttlebody"
As soon as you understand this, you will understand why you're wrong.
I've been doing a fair bit of research on this myself... I have to agree with BuickGN. Unless the car is carbureted, you're not going to have mileage gains, only performance. It's really a matter of fact and there is no point in arguing it.
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