TV mileage improvement-K and N filters

[lwbfl]

So you actually believe that non-economy vehicles get the best balance of power and MPG from the factory?  Why then can I re-program the computer and get more power and more MPG?  I agree that the economy car's get the most for that reason, but there is no reason a full size truck should have 300hp and get 17mpg from the factory.  If you think there is no link between the manufatures and the oil industry then you should look alittle deeper into the subject.  No offence, but being a service manager has nothing to do with the design of the vehicles and thier programming.

[AustinBoston]

So you actually believe that non-economy vehicles get the best balance of power and MPG from the factory?  Why then can I re-program the computer and get more power and more MPG?

Because you probably don't, atleast not both.  Even if you do, that doesn't mean the next guy will even if he does exactly the same thing; he probably won't either.

I agree that the economy car's get the most for that reason, but there is no reason a full size truck should have 300hp and get 17mpg from the factory.

It's called thermodynamics.  There are physical laws in the world that even GM can't break.

If you think there is no link between the manufatures and the oil industry then you should look alittle deeper into the subject.  No offence, but being a service manager has nothing to do with the design of the vehicles and thier programming.

You might look into the fuel-efficiency based fleet taxes the auto manufacturers pay.

Austin

[wavery]

So you actually believe that non-economy vehicles get the best balance of power and MPG from the factory?  Why then can I re-program the computer and get more power and more MPG?  I agree that the economy car's get the most for that reason, but there is no reason a full size truck should have 300hp and get 17mpg from the factory.  If you think there is no link between the manufatures and the oil industry then you should look alittle deeper into the subject.  No offence, but being a service manager has nothing to do with the design of the vehicles and thier programming.

I'm not offended. You just obviously have little or no knowledge of the industry. That is completely understandable, if you've never worked in the industry.

Dealership Service Managers are the eyes & ears of the manufacturer. I was highly trained on all aspects of vehicle design & programming.

Actually, I spent 4 years at General Motors Institute. I worked as a Factory Rep for a few years, then discovered that I could make a lot more $ as a Dealer Service Manager. While working as Service Manager, I spent hundreds of hours per year in factory training classes (more than most doctors). Dealer Service Managers have a tremendous amount of input to the factories pertaining to R&D and product reliabilty.

To think that a Service Manager "has nothing to do with the design of the vehicles and their programming" is like saying that a farmer has nothing to do with with the quality or production of the crops that he sends to market or a doctor (Human Service Technician) has no knowledge of the design or programing of the human body.

As for your question, "Why then can I re-program the computer and get more power and more MPG?". The manufacturer is well aware of the different tweaks that can be done to their computerized fuel injection systems. If you are talking about the various computer chips that are available for "Increased Performance", most are fraud. The ones that actually do increase performance do so by changing the timing and fuel mixture ratio at various RPMs and air pressure readings in the intake manifold. The manufacturer is restrained by emission laws (as I previously stated) and vehicle reliability, over time.

Don't you think that the manufacturer would prefer to add 20HP to their advertised specs by merely changing the programing on their computer? That's a no brainer and would cost little to nothing during manufacturing. It would obviously add $ to the sticker price of each vehicle (pure profit). Why would you think that there is an up-side to not put out the same computer chip as the "Performance" suppliers? Trust me, all of the manufacturers are well aware of what they can do to enhance the performance of each model. They have many more factors to consider than some guy that is putting out an aftermarket part and clearly states on their packaging that they are not responsible for any damage that the part may cause to the vehicle. Most of those parts are clearly marked, "For off-road applications only" to avoid local and federal laws.

The manufacturers carefully analyze every tiny detail that effects the extremely complicated product that they supply to the public. You would be amazed at the the number of people  departments from design and engineering to financial and legal that are involved in every tiny nut, bolt and programming that goes into each individual part of every model.

When you added that chip to your vehicle, did you add 10% more cooling capacity to your cooling system? Did you install 10% tougher, pistons, rods, rod bearings, valves, valve springs and other high energy engine components? Did you re-design your transmission, final drive and wheels to handle 10% more HP? Of course you didn't. These are just a few of the things that the manufacturer must take into account when designing the over-all vehicle. The computer chip is nothing. It's all the ramifications of adding the additional HP that could add hundreds if not thousands to the sticker price. Have you ever wondered why High Performance factory vehicles cost so much? These are just a few of the reasons.

I hope that I have helped answer you question about, "Why then can I re-program the computer and get more power and more MPG?".

[flyfisherman]

I believe the best way to improve your gas mileage is probably to slow down. I won't go into all the details, but I kept very close watch on my mileage on my long trip (4800 miles) in July. I kept notes on all sorts of variables like speed, gas grade, towing vs not towing, AC vs no AC, hills vs flat, and so on. The biggest improvement seemed to me to be consistently related to my speed. Slowing down even 3 or 4 miles per hour made a measurable difference.

I keep a log on my traveling, too, and have come up with the same conculsions.
Have an '02 GMC 1500 Sierra pick'em up, short wheel base, small V-8, automatic, 2 whl drive; Has one of those low profile (fiberglass) cargo bed covers.

As gas prices began to climb I began to experiment on my driving habits and speeds. Had to make a trip up to Raleigh, NC, and I topped the truck's fuel tank at Wilmington, NC, then got onto I-40, a direct x-way shot to where I needed to go for a distance of 125 miles+. Set the cruise at 55 and cruised on down the pike - whith everybody and their brother flying pass me! Got off I-40, topped the tank again, and I got a very surprising 23.7mpg. Not too shabby for a full sized, V-8 pick-up!  My destination in Raleigh was only a quarter of a mile off I-40 so there was hardly any city driving. Finished my business and got right back on I-40 only this time I set the cruise according to RPM's; I set it at exactly 1500, which equates to about 62mph. When I got back to Wilmington, topped off the tank again and this time I got 22.2 mpg. But on another trip, all expressway, I did the same thing, only at different speeds. At 65mph it dropped to 20.8 mpg; and on the return trip at 70mph, it dropped again to 19.9mpg. All this, of course, was not towing the Starcraft and being loaded to the gunnels.

My previous GMC pick-up had the 4.3 V-6 (really liked this engine) and it would do better on gas mileage, especially around town, but would drop below the V-8 mileage while towing (and under load) by at least 1 1/2 to 2 mpg - the extra horse power wins the day when doing heavy labor!


Fly

[Billy Bob]

As a graduate from Alfred State University in auto-mechanics one of the basic things you learn is you can't have it both ways. Either you give up mileage for more horsepower or you give up horsepower for better economy. The internal combustion engine will produce more horsepower in many different ways but the bottom line is the more air/gas mixture going thru the engine the faster you can go but you also use MUCH more fuel in doing so.

As posted here by several other WISE folks here, SLOWING down will produce better mileage and NO extra cost to you or your vehicle. That is why in the late 70's the Federal Government established the nation wide 55 mph on all federal financed roads. And you know what, it WORKED. Gas prices back then actually came down.

Bob

[wavery]

As a graduate from Alfred State University in auto-mechanics one of the basic things you learn is you can't have it both ways. Either you give up mileage for more horsepower or you give up horsepower for better economy. The internal combustion engine will produce more horsepower in many different ways but the bottom line is the more air/gas mixture going thru the engine the faster you can go but you also use MUCH more fuel in doing so.

As posted here by several other WISE folks here, SLOWING down will produce better mileage and NO extra cost to you or your vehicle. That is why in the late 70's the Federal Government established the nation wide 55 mph on all federal financed roads. And you know what, it WORKED. Gas prices back then actually came down.

Bob

That's exactly correct.

Some of the people on this board probably don't even remember that the speed limit, nation wide, was 55MPH for many years. This did lower fuel consumption somewhat. However, it also increased the number of hours that each vehicle spent on the road each year. It was determined that the lower speeds were contributing to traffic congestion so severely that either more lanes had to be added to all heavily traveled highways (at tremendous cost) or they had to change the total number of hours each of millions of cars spent on the road. The dynamics are just like a river, in order to get X amount of water down-stream the water must either move faster or the river must increase in size.

As China consumes more and more oil by their increased factory production and resulting vastly increased auto ownership and usage, we may find ourselves in a major oil crisis in this country. I can remember people having to camp-out at gas stations and spend 4-8 hours in lines that streched for blocks only to have the station run out as the line progressed. Many people simply couldn't get to work or school. Trucks couldn't deliver goods to the stores. That was a pretty frightening time and it is rapidly approaching again. Also, remember, we only have about 1/3 of the gas stations that we had at that time. In those years, there were literaly 2-4 gas stations at nearly every major intersection.

As you well know, the Arabs would much rather sell their oil to China than the US. Our Middle East policies may end up causing a LOT of changes in the way that we live our lives here in the US. I'm not saying that I disagree with our policies and don't mean to start a tirade there. I'm just saying that it will have personal consequences on the way that we live (period).

I fully expect the speed limit to be dropped to 55MPH again in the near future. We are simply consuming more oil than we can produce or possibly obtain from foreign sources, over time, as competition for the product from other nations increase.

It is imperative that the US develop alternative sources of energy. President Bush (an oil man) has stated this on numerous occasions and the entire scientific and economic community has been stressing this. I fully expect that gas will exceed $5PG and if you have a gas guzzling vehicle you won't be able to give it away at that point. Trust me, all the mileage increasing products in the world are'nt going to make a dent in what is felt in your wallet, over time.

[lwbfl]

I respectfully agree to disagree with the idea that the oil and auto manufatures as well as the people who regulate these two, have no ties.  Look where 80% of our top governing personnel came from (big oil).  I also don't think that they have our best interest in mind, but profits.  I don't have personal experience, but I have family that works for GM and Ford at manufaturing plants.  I'm glad your not offended, as we are simply having discussion, not an argument.

[chasd60]

As a graduate from Alfred State University in auto-mechanics one of the basic things you learn is you can't have it both ways. Either you give up mileage for more horsepower or you give up horsepower for better economy. The internal combustion engine will produce more horsepower in many different ways but the bottom line is the more air/gas mixture going thru the engine the faster you can go but you also use MUCH more fuel in doing so.
 
As posted here by several other WISE folks here, SLOWING down will produce better mileage and NO extra cost to you or your vehicle. That is why in the late 70's the Federal Government established the nation wide 55 mph on all federal financed roads. And you know what, it WORKED. Gas prices back then actually came down.
 
Bob

With a solid background in automotives and a degree in Electromechanical Technology, I have to disagree.
 
The more air/gas was not what was stated. More efficient introduction of air is.
 
You seem to be saying that you cannot have engine A produce more HP and get better mileage than engine B. That is way too much of a blanket statement.
Just look at the cars and trucks available today and you will see that this reasoning is incorrect. A 4.8LChevy truck has more HP than an equivalent Dodge truck with a 5.2L and gets better mpg.
 
It boils down to efficiency not mpg per hp.
 
Slowing down increases mpg, agreed. Why? More so due to less aerodynamic drag and lower rolling resistance than vehicle engine rpm. The drag caused by the air is increased exponentially as speed increases.
 
None of that changes the fact that a more efficient combustion process will perform more efficiently at any speed.

[chasd60]

I see alot of negative responses to this topic from people that have no real experience with the product mentioned. You have no credibility with those that have used the product and have seen gains. Your input is not based upon personal experience.
 
Don't forget the originator of this post HAS a K&N filter and he HAS CALCULATED a gain due to a more efficient method of introducing combustion air.
 
I have used the product in question and I have had gains. There are other filtration methods that use more surface area to get the same gains without the use of oil saturated filtration methods.
 
Most agree that if you change a dirty air filter you will improve the mpg's. Why would that help? Might it be that you have reduced the power required to pull the air into the intake from a clean filter vs a dirty one? Is that not the same reasoning for changing to a filter that reduces the power required to pull air into the intake vs a stock filter?
I think I see a direct relationship here?
Anyone else?

[wavery]

I see alot of negative responses to this topic from people that have no real experience with the product mentioned. You have no credibility with those that have used the product and have seen gains. Your input is not based upon personal experience.
 
Don't forget the originator of this post HAS a K&N filter and he HAS CALCULATED a gain due to a more efficient method of introducing combustion air.
 
I have used the product in question and I have had gains. There are other filtration methods that use more surface area to get the same gains without the use of oil saturated filtration methods.
 
Most agree that if you change a dirty air filter you will improve the mpg's. Why would that help? Might it be that you have reduced the power required to pull the air into the intake from a clean filter vs a dirty one? Is that not the same reasoning for changing to a filter that reduces the power required to pull air into the intake vs a stock filter?
I think I see a direct relationship here?
Anyone else?

I can see your logic. The problem is, the vehicle is VERY carefully designed for the CFM that the stock filter allows through. Granted, removing the air filter completely will allow the intake to a slightly higher increase in CFM. However, under anything less than full throttle, the increase of HP from the almost imperceivable amount of additional available air would hardly be measurable. The fact is, changing the air pressure in the intake chamber will be overridden by the on-board computer to richen the fuel mixture to maximize combustion.

The air/fuel mixture is carefully monitored by the computer and it will remain constant at various throttle pressure. If you increase available air, the computer will introduce additional fuel to compensate. This may result in what is perceived to be a "Quicker throttle response" (especially with no load) but it does little for HP or fuel economy. The only exception would be at full throttle when vacuum reaches close to zero and any additional air will increase HP because it will allow additional fuel to keep that optimum ratio (however, very slightly in this case). That is the advantage that superchargers give you. They will actually force air and develop a positive air pressure in the intake chamber. The result is an increase in HP as much as 25% (at full throttle) because the vehicle can then accept more fuel and maintain the same air/fuel ratio.

The 350CI Chevy engine today is basically the same engine that was used in the 60s & 70s. In the 70s those vehicles were getting less than 20MPG. Today, they are getting 25-30% better. Why is that? Did they change the laws of physics? Did they install better breathing air filters? No to both. #1 contributer is a better weight to HP ratio (they build the cars lighter). #2, they have introduced computerized fuel injection technology. They have a better ability to monitor and control the air/fuel mixture under a variety of conditions. They couldn't do that with carburetor cars. The biggest loss of efficiency was the inability to control that ratio under differing conditions. That's it. It's just as simple but complicated as that.

Now, there are engines that use that air/fuel ratio more effectively to produce more HP per CI of engine. It usually is accomplished by better intake & exhaust valve systems that allow the engines to run more efficiently at higher RPMs. This combined with even lighter cars, accomplish a better weight to HP ratio. THAT is the ratio that really counts. If you want to get better MPG, you are far better off lightening your load than adding an expensive air filter that does nothing but allow more engine noise to come through.

As was stated before, you are simply talking about laws of physics here. There is an optimum air/fuel ratio for every vehicle and it varies very slightly with the size of the engine and the load put on it. You cannot add more air and make more HP without adding the amount of fuel to maintain that optimum ratio. The idea that it takes "HP" to suck air into the engine just isn't viable. Your optimum fuel economy is achieved when the vacuum pressure in the intake manifold is at it's highest. The idea of adding more air into the intake would effectively decrease the vacuum.

IMO, the science behind these filters just doesn't wash. IMHO, it's all effective merchandising and the "Sound" that the filter allows through that gives the consumer the impression of power. After-all, no one wants to believe that they wasted their money buying one of these set-ups.

[lwbfl]

MY Z-71 had a drop in K&N when I bought the truck.  I wouldn't spend the money on a K&N, but I do like the fact that I don't have to keep buying the paper filters.  No problem to wash it with a hose and spray some oil on it as instructed.  I like to tinker with my stuff anyway.  I disagree with the allowing more air in will not increase power.  Does the injection system not monitor the air flow and adjust the fuel to this variable?  I know the old MAS systems did.  Also, if we were talking about carberated engines, it would be much different.

[wavery]

MY Z-71 had a drop in K&N when I bought the truck.  I wouldn't spend the money on a K&N, but I do like the fact that I don't have to keep buying the paper filters.  No problem to wash it with a hose and spray some oil on it as instructed.  I like to tinker with my stuff anyway.  I disagree with the allowing more air in will not increase power.  Does the injection system not monitor the air flow and adjust the fuel to this variable?  I know the old MAS systems did.  Also, if we were talking about carberated engines, it would be much different.

I hope that this may help some understand this better:
http://en.wikipedia.org/wiki/Air-fuel_ratio

[chasd60]

Every automobile and or truck does not have the perfect intake nor exhaust system. These systems were designed to be mass produced and some of them are much less efficient than others from the tubing that feeds the filters to the bends in the exhaust system. It is not unreasonable to believe that some vehicles will actually gain mpg and hp with these simple mods. Granted, the degree of gain will be directly related to the improvement in the new design over the original. I think it is unreasonable to believe that every system is actually the perfect design from the factory. You don't add more air to the system, you have a less restrictive path of delivery which definitely leads to quicker throttle response and sometimes increased fuel economy.
 
The stoich mixture is another can of worms in itself. The ratio of 14.7 to 1 is a trade off. Part of the fuel is burned in the combustion process and the rest blows the combustion kernel out and cools the exhaust valves. That is why a lean mixture is known to burn the valves. That is also why there is a catalytic converter. The computer adjusts the air/fuel ratio for a predetermined amount of pollution. The catalytic converter burns off the unburned fuel that cooled the exhaust valves.
 
I installed a bubbler in a float tank with gasoline and pulled air through the bubbler with engine vacuum directly into the intake. The gasoline vapors provided a very efficient fuel source. The vapors supplemented the liquid fuel source.
The O2 sensor sensed a lean mixture and added more liquid fuel to achieve that predetermined amount of pollution. I added an O2 sensor offset to fool the computer into measuring a lean mixture as a rich mixture and this caused the computer to send a signal to lean out the liquid fuel portion.
The increase in MPG's was about 20% and the exhaust was actually cleaner than the regular process.

[wavery]

Every automobile and or truck does not have the perfect intake nor exhaust system. These systems were designed to be mass produced and some of them are much less efficient than others from the tubing that feeds the filters to the bends in the exhaust system. It is not unreasonable to believe that some vehicles will actually gain mpg and hp with these simple mods. Granted, the degree of gain will be directly related to the improvement in the new design over the original. I think it is unreasonable to believe that every system is actually the perfect design from the factory. You don't add more air to the system, you have a less restrictive path of delivery which definitely leads to quicker throttle response and sometimes increased fuel economy.
 
The stoich mixture is another can of worms in itself. The ratio of 14.7 to 1 is a trade off. Part of the fuel is burned in the combustion process and the rest blows the combustion kernel out and cools the exhaust valves. That is why a lean mixture is known to burn the valves. That is also why there is a catalytic converter. The computer adjusts the air/fuel ratio for a predetermined amount of pollution. The catalytic converter burns off the unburned fuel that cooled the exhaust valves.
 
I installed a bubbler in a float tank with gasoline and pulled air through the bubbler with engine vacuum directly into the intake. The gasoline vapors provided a very efficient fuel source. The vapors supplemented the liquid fuel source.
The O2 sensor sensed a lean mixture and added more liquid fuel to achieve that predetermined amount of pollution. I added an O2 sensor offset to fool the computer into measuring a lean mixture as a rich mixture and this caused the computer to send a signal to lean out the liquid fuel portion.
The increase in MPG's was about 20% and the exhaust was actually cleaner than the regular process.

Maybe I'm mis-reading you here but it sounds to me like you are saying that you used to blow 1 gallon of every 5 gallons of gas, out your exhaust pipe as unburned fuel. That seems pretty extreme but I suppose that it's possible.

I get a little skeptical any time that someone tells me that they have conducted a fuel economy test on their car (I'm not talking about your scenario chasd60) . I keep very careful records of my fuel consumption every time that I fill my tank. We have been driving down to Fallbrook California from Beverly Hills every weekend for the last 6 weekends (we bought a house that we are fixing up to rent). It's 106 miles each way. I fill up before we leave and again when we return. I use the same station every time. My mileage is all over the place. It varies from 24-29.4 (almost a 20% variance) on my 2001 Chrysler Concorde. I always set the cruise on 75 and try to drive with no traffic. There are always different contributing factors. IMO about the only way that you could truly tell if you are getting a 10% better mileage is to run the test on a dyno in a lab. Something as simple as a 5MPH breeze on the nose going one way and a 5MPH breeze from the rear going home could make a big difference in gas mileage. Driving at 75 with a 5MPH headwind will give you the same resistance as driving 80. Doing 75 with a tailwind of 5MPH will give you the resistance of 70. That 10MPH difference in wind resistance could easily make a 10% difference in gas mileage. There are other factors like barometric pressure, humidity and temperature that all come into play as well.

[Camping Coxes]

Okay.  I'm telling you up front that I'm a female type person and don't understand 99% of the arguing I see on this board.  The original question was about opinions on the K&N filter.  My DH has a 1984 Diesel Suburban.  He is a major gearhead and does most of our auto repairs himself.  He purchased the K&N on recommendation from a diesel site he belongs to.  He has been very impressed with the K&N and has recommended it to several friends who have subsequently bought diesels.  He purchased his at NAPA auto parts.