Mustang GT and K&N air charger

These web sites were developed after EFI was common place. The .gov site is from the US Dept. of Energy and is very current. The Edmunds site is also very current. The last one is put up by the State of Massachusetts. These aren't old out of date web sites. Do a Google search and you'll have weeks of reading that tells you that dirty air filters decrease gas mileage on ALL cars.

Try this one:

Expand the link to "Do I need a new air filter?" Look at the third item listed. Do you think this site is referring only to engines with carburetors? Do you think Ford's Genuine Parts and Service web site is giving out bogus information on this topic? Are the thousands of sites saying dirty air filters decrease gas mileage all wrong. Can you find a site that says dirty air filters DON'T decrease mileage? I can't believe we are even arguing the point, to be honest.

Doesn't matter, the way it was clogged nothing would have been able to run.

Does the load tables in the ECU increase A/R as the load increases? Does the throttle position sensor help the ECU determine the engine load? Does a dirty filter require the throttle to be further open to make the same amount of power as it does with a clean filter? Does running the engine at a lower A/F decrease gas mileage?

You are splitting hairs. An air filter can operate within parameters for 15,000+ miles but it is progressively getting more resticted and progressively decreases gas mileage. If you chose to you could drive around without an air filter at all and you'll get better mileage that if you used an air filter. EFI cars have BAP (Barometric Air Pressure) sensors to allow for adjustment of A/F due to air density changes from varying altitudes. This tells the ECU that the engine isn't necessarily under an increased load because driving in high altitude areas requires the throttle to be more open compared to near sea level driving.

The core question is does a dirty air filter decrease gas mileage? It does. How much depends on the amount of dirt in the filter and its restriction to flow. The highest rate of flow for an air filter is when it is new. After that it decreases and therefore mileage decreases. The reason is that as the filter gets dirty it causes the ECU to use ever more richer target A/F ratios based on its hard wired load tables in the program code because the throttle position has to be progressively more open as the filter collects more dirt in order to make the same amount of power.

The throttle position readings are much finer than you think. The load tables (there are more than one) in the ECU have numerous rows and columns to read from. Going from 0.2 volts to 0.98 volts is is a large range when you are reading to the hundredth of a volt. If the air filter restriction is enough for the ECU to jump just one slot then mileage has been decreased. There are enough "slots" that it can read for the gradual drop in mileage to be imperceptible from one tank of gas to the next. However, if you compare mileage over a greater time interval you can see a difference. Most people use visual inspection to determine when the filter gets changed and not mileage decreases. If it looks dirty then it is probably time to change it before the mileage decrease becomes too high and/or noticed.

Yes it does because a dirty air filter mimics the engine being under a load from the viewpoint of the ECU. That is how the ECU reacts and why gas mileage falls.

If you change the air filter before it gets too dirty then you won't notice the small decrease in gas mileage that occurs over the filter's useful life. What happens to gas mileage when you fail to change the air filter on a timely basis?

So you are agreeing that a dirty filter does decrease gas mileage (or effect emissions) and the degree it is decreased depends on how dirty the filter may be?

As an air filter becomes dirty it gradually decreases mileage. It is a trade-off between acceptable mileage decrease and the economics of changing the filter. In the era of quick lube places checking filters with an oil change, most people never have an air filter get so clogged that it causes a drastically noticeable change in mileage or black smoke coming out of the tail pipe. None the less, gas mileage does decrease over the life of an air filter.

You are giving too much credit to an ECU's ability to "think". It operates from tables and not from computing Bernoulli's Principle thousands of times a second. It reads sensor data, looks up a value(s) from a table and then outputs commands based on those table values. Those tables don't take into account a dirty air filter in any way. If the air filter is dirty enough to cause the throttle to be more open then it can only read this input as the engine being under a load. Then is reads from the load table to run at a lower A/F ratio. This decreases gas mileage. Sometime by a little and sometimes by a lot depending on how dirty the filter may be. The ECU doesn't have "the filter may be dirty" parameter anywhere in its programming.

They all want you to replace consumable parts more often then needed. That makes them more money.

It depends on if the K&N flows enough for the ECU to think the engine is under a lighter load than when using an OEM filter. If it does then mileage will increase. I would guess that a K&N would decrease mileage at a slower rate than an OEM filter would because it will flow more air if both filters receive the same amount of dirt. Whether it is noticeable is up for debate.

Erosion doesn't happen with proper farming techniques.

No and no.

Again, using proper farming techniques top soil won't be depleted.

Farmers use fertilizer much the same way people use vitamin pills. Farmers abuse the soil and then rely on the "quick fix", just like people eat wrong and then relay on the "quick fix" of vitamin pills.

That's only because production (farming) hasn't caught up with the new demand. Just add more farms, or switch to other crops for biofuels.

You don't stop terrorism with war. War causes terrorism.

Agreed.

Can't or won't?

But if two counties begin fighting over the [oil] spicket because they can't get enough to power their cars, heat their homes and run their factories will cooler heads prevail?

I think terrorism will be the new low-level war technique. Just pay a guy to strap on a bomb to get your nation's point a cross. Make sure all the tracks are covered, later deny any involvement and then sit back and reap the fallout.

Patrick

The trouble is that 99% of farmers don't use those techniques and if they did the impact of crop yields would be substantial.

An example is that corn will deplete the top soil of nitrogen and soybeans put nitrogen back into the soil. This is why these two crops are rotated when and were possible. The trouble is that corn is more in demand and generates more product per acre so they need to supplement with fertilizer in order to plan corn year after year. The Midwest enjoys a thick blanket of top soil that developed over the eons but it is being reduced much faster than it is being replaced in heavily farmed areas. I agree that there are ways to farm that can slow this process down substantially but these methods usually result in lower yields and most farmers won't use them for this reason.

This is where I have the problem. More planting means more fertilizer, more erosion etc. Even then biofuels won't make much of a dent in our oil import volumes or in meeting our energy needs. There is already an impact on food prices and biofuels is in its infancy. It isn't only us here in the USA that will be affected. We feed a large part of the world and if we divert our food resources for energy production there will be even more starving people in the poor areas than there are today. If you think countries will fight over oil resources what do you think they will do for food?

Do you think the Islamic extremists will stop trying to kill us if we sit in the Lotus position and start singing Kum Ba Yah? I don't think they will. We are talking about people that think "Honor Killings" are perfectly acceptable. They chop off hands and feet for stealing. They stone people to death for adultery. They treat women like slaves. Do you really think they can be reasoned with? They push the Islamic religion like the Soviet Union pushed communism. They are like the Borg from Star Trek. If you don't convert to their belief system then you need to be killed.

Won't or can't the result is the same. Interests of countries today are no longer bound by national borders.

Nuclear capable countries will fight each other over food before oil. I think many in this country, including the government, know the end is near for obtaining cheap oil. Hybrids are the first step in getting plug-in cars to the consumer and when that happens and those cars have a decent range we will see the dominoes fall real quick on the internal combustion engine.

The problem with a nation making war is they have something to lose. There is territory, infrastructure, population etc. that can be destroyed or taken. Terrorists are nomads that have very little to lose and are willing to die for their cause. It is also something that will never go away. Fighting it is like playing an unending game of Whack-A-Mole.

Uh, not true. Modern farming means no-till farming, which causes far less erosion than previous practices. For starters, see:

Oh come on, man. You know that the age of the web site does not indicate the age of the content. So again, I ask: Do you have any URLs for tests done with modern engines?

Do you have any? Feel free to make an effort. It's not my job to do your homework to support your claims. I gave you my links now you give me yours.

Have you been to many cultivated fields lately? No-till farming has been around for decades (far from being modern) and it still hasn't been adopted by many serious farmers that are in it to make a profit. You do know that the first step in no-till farming is to dump weed killer on the fields to kill ALL the plant life before the crop seeds are knifed into the soil?

My first job out of college in the early 1980s was with a local Soil and Water Conservation District in Virginia and when we would mention no-till farming to a farmer his eyes would roll. The reaction hasn't changed over the years when the question is asked. It all sounds good until the farmer sees the crop yields in the fall from a no-till field. Farmers are businessmen much more than they are environmentalists.

****lots of previous stuff removed*****

I'll take one last stab at this.....

The basis of your argument seems to be that automotive engineers are idiots who cannot design a fuel injection system that will compensate for a minor difference in the flow restriction of an air filter. I don't believe this to be the case.

I dug out the Ford shop manual for a 1999 Mustang 2V 4.6 Liter engine. The PCD includes TPS reference voltage values for a 1999 Mustang 4.6L V-8 - At idle the voltage is OK if it is anywhere between 0.52 and 1.27 V. At 30 mph, the acceptable range is 1 to 1.2 V. At 55 mph the acceptable range is 1.2 to

1.5 V. Clearly the tps value is not a major determining factor in adjusting the A/F ratio since the acceptable values at idle and 55 mph actually overlap. No other sensor related to the A/F ratio are affected by the air filter restriction. The only other sensors in front of the throttle plate are the MAF sensor and air temperature sensor. Neither will be affected by small changes in pressure in the intake tract related to the air filter restriction. A 1999 Ford 4.6L does not utilize a barometric pressure sensor.

The following sensor are part of the system:

Camshaft Position (CMP) Sensor -4.6L Crankshaft Position (CKP) Sensor -4.6L Throttle Position (TP) Sensor Idle Air Control (IAC) Valve -4.6L, (2V) Engine Coolant Temperature (ECT) Sensor -4.6L, (2V) Mass Air Flow (MAF) Sensor -4.6L, (2V, 4V) Intake Air Temperature (IAT) Sensor Heated Oxygen Sensor (HO2S) Catalyst Monitor Sensor Clutch Pedal Position (CPP) Switch Fuel Pressure Sensor

Except for the TPS, none of these will be affected by normal sorts of changes in the air filter restriction. As I have tried to explain previously, the TPS is just a gross indicator of the throttle position. It is not designed to be used for the sort of fine A/F ratios you are suggesting it is used for. The range of acceptable output valves for a given throttle position is so wide that it cannot possibly be a determining factor when evaluating changes in fuel economy as a result of changes in air filter restriction.

The following is from the PCD manual for a 1999 Mustang:

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"Fuel Trim

The fuel control system uses the fuel trim table to compensate for normal variability of the fuel system components caused by wear or aging. During closed loop vehicle operation, if the fuel system appears "biased" lean or rich, the fuel trim table will shift the fuel delivery calculations to remove the bias. The fuel system monitor has two means of adapting Short Term Fuel Trim (FT) and Long Term Fuel Trim (FT). Short Term FT is referred to as LAMBSE and Long Term FT references the fuel trim table.

Short Term Fuel Trim (Short Term FT) (displayed as SHRTFT1 and SHRTFT2 on the NGS tool) is a parameter that indicates short-term fuel adjustments. Short Term FT is commonly referred to as LAMBSE. LAMBSE is calculated by the PCM from HO2S inputs and helps maintain a 14.7:1 air/fuel ratio during closed loop operation. This range is displayed in percentage (%). A negative percentage means that the HO2S is indicating RICH and the PCM is attempting to lean the mixture. Ideally, Short Term FT may remain near 0% but can adjust between -25% to +35%.

Long Term Fuel Trim (Long Term FT) (displayed as LONGFT1 and LONGFT2 on the NGS tool) is the other parameter that indicates long-term fuel adjustments. Long Term FT is also referred to as Fuel Trim. Long Term FT is calculated by the PCM using information from the Short Term FT to maintain a 14.7:1 air/fuel ratio during closed loop operation. The Fuel Trim strategy is expressed in percentages. The range of authority for Long Term FT is from -35% to +35%. The ideal value is near 0% but variations of ±20% are acceptable. Information gathered at different speed load points are stored in fuel trim cells in the fuel trim tables, which can be used in the fuel calculation.

Short Term FT and Long Term FT work together. If the HO2S indicates the engine is running rich, the PCM will correct the rich condition by moving Short Term FT in the negative range (less fuel to correct for a rich combustion). If after a certain amount of time Short Term FT is still compensating for a rich condition, the PCM "learns" this and moves Long Term FT into the negative range to compensate and allows Short Term FT to return to a value near 0%.

As the fuel control and air metering components age and vary from nominal values, the fuel trim learns corrections while in closed loop fuel control. The corrections are stored in a table that is a function of engine speed and load. The tables reside in Keep Alive Random Access Memory (RAM) and are used to correct fuel delivery during open and closed loop. As changing conditions continue the individual cells are allowed to update for that speed load point. If, during the adaptive process, both Short Term FT and Long Term FT reach their high or low limit and can no longer compensate, the MIL is illuminated and a DTC is stored."

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And finally, here is a challenge for you. The chart below lists the average fuel economy over 900 to 1250 mile intervals for my 2006 Nissan Frontier - tell me approximately at which points the air filter was changed......should be a piece of cake if filter restriction affect fuel economy as drastically as you think. This truck is a farm vehicle and spends a significant amount of time on dirt road and field paths. It probably saw more dust last October than your Mustang has ever seen (I pick peanuts in October - almost nothing generates more dust).

Cum. Avg Miles MPG Since previous period

------- --------------------- 1176 18.1 2132 18.9 3274 19.0 4234 17.9 5276 18.2 6433 17.2 7358 18.7 8488 18.9 9540 18.8

10666 18.1 11812 19.2 12888 19.3 13995 19.2 15230 18.6 16276 19.1 17425 19.0 18518 17.9 19454 18.6 20444 19.0 21375 18.1 22423 18.1 23543 18.4 24684 18.2 25684 18.8 26895 18.9 27889 19.3 29045 17.7 30199 19.3 31203 18.8 32151 20.1 33175 19.6 34236 19.7 35313 20.5 36396 18.9 37403 19.3 38325 19.6 39306 19.9 40275 19.5 41311 19.8 42494 18.6 43721 19.2 44685 18.2 45757 18.8 46686 18.8 47745 18.7 48456 19.3

Ed

"Michael Johnson" wrote in message news:ZfGdncVhlKVNWRPanZ2dnUVZ snipped-for-privacy@giganews.com...

Not only have I seen no-till fields - I have planted fields that way (Northeastern NC). I would plant all my soybeans that way if I had a good no-till drill. As it is, I borrow my neighbors no-till drill to plant beans behind small grain. For my type of soil, I don't believe no-till is appropriate for corn or peanuts. However one of my neighbors has been very successful at planting no-till cotton. I don't personally raise cotton, but if I did, I would no-till most of my cotton crop. The majority of winter wheat in my area was planted no-till this year, and the majority of soybeans planted behind the wheat will be no-till as well. If I had the proper equipment I would try at least one field in no-till corn. I have a neighbor who is trying it. I'll keep my eye on the results. If he is successful, I would love to go that way. The saving in planting time alone would make it attractive if the yields are within 10% of conventional planting. The business man in me would love to save the time and money consumed by conventional field preparation operations. The biggest thing holding me back is the cost of new no-till equipment. Commodity prices have been so depressed over the last 25 years that it is all I can do to maintain the equipment I have. I haven't purchased a new farm tractor since 1991. Converting to no till would cost me at least $100,000. If I thought the current moderate prices would last, I would consider buying at least a no-till seed drill and the larger tractor I would need to handle it. I have little faith that the prices won't drop back to depression era levels shortly. As I mentioned before, unadjusted corn prices last year were no higher than in 1975. Adjusted for inflation, they were as low as during the great depression. Only very large farmers can make a decent living farming these days. I farm twice the acreage my Father did, with half the labor (around 350 acres). He made his living farming and sent three children through college and graduate school. I make barely enough from farming to cover the payments on my farm land. I have a "real" job to support myself and my children.

Ed

My guess is you have soil with a high sand content where no-till works better. In other areas the soil is more compact and the plant's root system has a much harder time propagating through the soil. In the Midwest and here in Virginia it is very rare to see a no-till field. Especially, on farms that require high production to be profitable. How is your yield on the no-till compared to conventional till? I know the cost to plant is supposed to lower but the rub is the yield is lower too.

When I was growing up in Indiana there were many full time farmers that could make a living off of as little as a thousand tillable acres. Nowadays someone farming 1,000 acres would barely scratch out a living there. Farming became a corporate business a long time ago.

"Michael Johnson"

Actually soybeans are more profitable than corn for many farmers at the current prices. Soybeans are pushing $10. Good farmers can easily make 50 bu per acre, for a $500 acre gross income. Corn is around $2.50. 200 bu per acre corn will all generate a gross income of $500 per acre. However, corn is much more expensive to raise. The fertilizer cost for corn is two or three times that for soybeans. On the other hand, you cannot continually plant soybeans to the same field year after year. There are numerous diseases that affect soybeans that build up in the soil if you continually plant soybeans to the same field. Corn on the other hand is very disease resistant, so it can be planted to the same field repeatedly. Cotton also is relatively disease resistant and can be planted to the same field in back to back years (but it is even more expensive to raise than corn). A good rotation would be soybeans, corn, cotton, soybeans. Unfortunately cotton prices are weak at the moment, so a lot of people are doing corn-soybeans-corn-soybean rotations. If the profitability balance shifts towards corn, then a more desirable rotation would be corn-corn-soybean-corn-corn-soybeans. Personally I am decreasing my corn acreage this year by 30% and am replacing it with soybeans. I also am increasing my peanut acreage this year. The weak dollar might be bad for people buying imported goods, but it is a godsend for farmers. The current moderate price levels for farm commodities has more to do with the weak dollar than with corn being diverted to ethanol production.

At this point the impact of ethanol on food prices is trivial. The weak dollar and increases foreign demand has more to do with higher prices than ethanol production. Although somewhere around 25% of US corn is used in ethanol production, this does not translate into a 25% increase in demand for corn. After the corn is used to produce ethanol, the dried mash is a very high quality animal feed. This mash offsets almost as much corn as is consumed to make ethanol. The net effect on the animal feed supply (most corn is used as animal feed) is probably less than 5%. If you are really worried about global food supplies, you should cut out meat consumption. It takes somewhere around 3 lbs of corn to produce 1 pound of cow. If the US cut meat production by 50%, we would be awash in corn.

There is more than adequate food in the world to feed everyone alive today. The problem is economics. We have plenty of extra capacity in the US, but unless you are going to organize a better distribution system, and figure out how to pay for the food, people will continue to starve. Exporting food from the US to poor countries is not the answer. These people need stable goverments and the tools to produce their own food. I recently read an article criticizing US farmers for producing commodities at too low a price. For much of the world it is cheaper to buy commodities like cotton from the US than to invest in growing them at home.

Ed

Try

or . This is a reprint of a Consumer Report article. Here is the relevant portion - "IMPORTANT DRIVING TIPS THAT HAVE LITTLE EFFECT ON FUEL ECONOMY ....

"Keep your air filter clean. According to our tests, driving with a dirty air filter in modern engines doesn't have a significant impact on fuel economy, as it did with older engines. While fuel economy didn't change, however, power output did. Both cars accelerated much more slowly with a dirty air cleaner. We drove both vehicles with their air cleaners restricted and found little difference in gas mileage with either engine. That's because modern engines use computers to precisely control the air/fuel ratio, depending on the amount of air coming in through the filter. Reducing airflow, therefore, caused the engines to automatically reduce the amount of fuel being used."

Ed

Crops fall under the laws of supply and demand too. Soybeans are a big component of what gets planted in the Midwest. Corn is king but soybeans are the queen. The weak dollar is good for many people/industries here in the USA. A lower dollar value is about the only way many manufacturing jobs will stay within our borders.

As I mentioned in another post, it is a standard of living issue and in this country giving up meat is like taking away the air we breath. I watched a Modern Marvels show about corn and I was amazed at all the products that require corn. It is in many things that most people would never guess.

Farming has become an industry just like many others in that small volume producers aren't competitive anymore. Economy of scale is now applied to farming like many other manufacturing sectors.

> or . This is a reprint of a Consumer Report > article. Here is the relevant portion ->

Notice the part where is states "driving with a dirty air filter in modern engines doesn't have a significant impact on fuel economy"? This means it did have an impact on fuel economy. What we don't know is their definition of "a dirty air filter" and "a significant impact". Maybe what they consider insignificant to them isn't insignificant to someone else. They are actually confirming that a dirty air filter does impact gas mileage. Had they used a filter with enough dirt in it then they would have seen a substantial impact on mileage.

>> or . This is a reprint of a Consumer Report >> article. Here is the relevant portion ->>

You failed English 101. And Logic 101. That CR statement could well mean that there was no measureable impact; i.e., either little or *none*.

>> or . This is a reprint of a Consumer Report >> article. Here is the relevant portion ->>

GEEEEEEEEEZ - Nobody is claiming that sticking a potato in the intake won't screw things up. This whole discussion got started because you objected to my contention that a K&N air will not significantly improve the fuel economy of a modern fuel injected engine. We are talking about a difference in filter restriction of less than a tenth of a psi at wide open throttle. At a steady state cruise the difference is even less (probably hundredths of a psi). If you want to compared some hypothetical completely plugged filter to a filter replaced at reasonable intervals, then I won't claim there isn't a difference. But if we are just talking about filters operating in the normal range of contamination one would expect to see for a properly maintained engine, then the air filter is a not going to have a significant effect on fuel econonmy. And I stand by my statement that ther is no reason to expect a K&N air filter to provide a significant (= measurable) improvement in the fuel economy of a modern fuel injected engine [compared to a reasonably well maintained paper filter].

Ed

Ed