Thinking of adding a K&N kit on my 2008 Colorado 2.9 automatic. Anyone have any before/after mpg numbers?
Does a cold air intake improve gas mileage?
- Thread starter cousincletus
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It depends on the design of the factory air intake system. Some are efficient and you will see no gains or improvement with an aftermarket CAI. While in other less efficient factory designs, an aftermarket CAI can improve MPG efficiency.
Also keep in mind that depending on design, a CAI usually takes away low end power, while adding a little more pep on the top end.
Also keep in mind that depending on design, a CAI usually takes away low end power, while adding a little more pep on the top end.
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It may make a slight difference but I am wondering if you will ever recoup the expense of the equipment over the life of the vehicle?
Proper tire pressure and driving habits would make more of a difference in my opinion for what it is worth.
Proper tire pressure and driving habits would make more of a difference in my opinion for what it is worth.
I wouldn't. It has been seen through various "UOA's" (used oil analysis) that k&n filters = higher silicon numbers. I did all the mods on my 98 jeep wrangler (cold air kit, Throttle body spacer, bored throttle body, high flow exhaust) and just got a lighter wallet. No real difference in mpg but I did feel a slight "butt dyno" difference.
I would suggest Keep a quality paper filter like a purolater pure 1 and change it every 30k.
With a pickup, I don't think any mod will get you an increase in MPG. Just keep it in good running condition and watch your right foot.
I would suggest Keep a quality paper filter like a purolater pure 1 and change it every 30k.
With a pickup, I don't think any mod will get you an increase in MPG. Just keep it in good running condition and watch your right foot.
Probably not enough to give you a payback. The mfgs do a pretty good job balancing out how the engine works as a package .You change this here which changes that there.
Don't do it. All the stuff between the atmosphere and your valves can sort of be summed up as one throttle. Remove air filter restriction and your throttle blade can close more for the same air intake and power output.
The only thing that changes with a better flowing filter is peak power output.
The only thing that changes with a better flowing filter is peak power output.
I know it's not the same vehicle but my f-150's intake air is the same as ambient within a couple of degrees according to my scanguageII. Unless GM has gone backward in design you're truck probably draws cold air already.
OVERKILL
$100 Site Donor 2021
Originally Posted By: Spartuss
Also keep in mind that depending on design, a CAI usually takes away low end power, while adding a little more pep on the top end.
How is something in FRONT of the MAF and TB going to take away low-end power?
Often the "butt-dyno" is confused by an increase in power above a certain point and thinks it has LOST power below that point.
Also keep in mind that depending on design, a CAI usually takes away low end power, while adding a little more pep on the top end.
How is something in FRONT of the MAF and TB going to take away low-end power?
Often the "butt-dyno" is confused by an increase in power above a certain point and thinks it has LOST power below that point.
Many cars come with factory cold air intakes.
All this means is that the inlet gets ambient air somehow, NOT under hood air.
Aftermarket intakes can get more power by having less convolutions and bigger piping, and colder outside air is better for power.
These are full throttle only benefits.
As noted above^, even non cold air intakes purge the hotter under hood air rather quickly once you are moving, so there is very little difference when you are moving.
But MPGs? I'd rather have warm air, esp in winter. I actually route my intake to the underhood for winter. Also, my old GTI had a winter/summer lever on the intake for this reason.
Some hypermilers use VERY hot air in the intake for best gas mileage. They are not concerned about power .
Run it too hot and you get a power loss, and possible pinging/spark knock .
All this means is that the inlet gets ambient air somehow, NOT under hood air.
Aftermarket intakes can get more power by having less convolutions and bigger piping, and colder outside air is better for power.
These are full throttle only benefits.
As noted above^, even non cold air intakes purge the hotter under hood air rather quickly once you are moving, so there is very little difference when you are moving.
But MPGs? I'd rather have warm air, esp in winter. I actually route my intake to the underhood for winter. Also, my old GTI had a winter/summer lever on the intake for this reason.
Some hypermilers use VERY hot air in the intake for best gas mileage. They are not concerned about power .
Run it too hot and you get a power loss, and possible pinging/spark knock .
Originally Posted By: cousincletus
Thinking of adding a K&N kit on my 2008 Colorado 2.9 automatic. Anyone have any before/after mpg numbers?
My dad added one on his 2008 Canyon with the 3.7 and there is a small increase and power and I think a slight increase in mpg. If you want to go with K&N do it, don't let people on here peer pressure you like they have been against K&N.
Thinking of adding a K&N kit on my 2008 Colorado 2.9 automatic. Anyone have any before/after mpg numbers?
My dad added one on his 2008 Canyon with the 3.7 and there is a small increase and power and I think a slight increase in mpg. If you want to go with K&N do it, don't let people on here peer pressure you like they have been against K&N.
OK, thanks for the comments.
Originally Posted By: OVERK1LL
How is something in FRONT of the MAF and TB going to take away low-end power?
That part of the intake affects the tuning too. The engineers who design the OEM intakes don't make them as small as they do because they're too stupid to realize that bigger is always better. For lower levels of power output, where most people drive most of the time, the OEM design will often provide more torque and better fuel economy. Of course, the OEM design also incorporates noise reduction, so that may offset the benefits of the smaller diameter intake.
Check out the dyno graphs from K&N and other manufacturers, and you'll find that many, if not most, only show the results above 3500 rpm.
Every design involves compromise, and a CAI usually compromises low-end torque, fuel economy, noise reduction, and filtration efficiency for peak power gains.
Fly-by-night companies may make fuel economy claims about their intakes because they have nothing to lose, but K&N makes no claims that its products increase fuel economy:
Originally Posted By: K&N
A lot of exaggerated claims are made in the marketplace by products claiming to improve gas mileage. K&N makes no general fuel economy claims, however we encourage you to try our air filter for yourself. Keeping air filter restriction as low as possible can be an important tool, among others, for maintaining high mileage. For more info read what some of our users have to say on the K&N testimonials page.
http://www.knfilters.com/filtercharger.htm
How is something in FRONT of the MAF and TB going to take away low-end power?
That part of the intake affects the tuning too. The engineers who design the OEM intakes don't make them as small as they do because they're too stupid to realize that bigger is always better. For lower levels of power output, where most people drive most of the time, the OEM design will often provide more torque and better fuel economy. Of course, the OEM design also incorporates noise reduction, so that may offset the benefits of the smaller diameter intake.
Check out the dyno graphs from K&N and other manufacturers, and you'll find that many, if not most, only show the results above 3500 rpm.
Every design involves compromise, and a CAI usually compromises low-end torque, fuel economy, noise reduction, and filtration efficiency for peak power gains.
Fly-by-night companies may make fuel economy claims about their intakes because they have nothing to lose, but K&N makes no claims that its products increase fuel economy:
Originally Posted By: K&N
A lot of exaggerated claims are made in the marketplace by products claiming to improve gas mileage. K&N makes no general fuel economy claims, however we encourage you to try our air filter for yourself. Keeping air filter restriction as low as possible can be an important tool, among others, for maintaining high mileage. For more info read what some of our users have to say on the K&N testimonials page.
http://www.knfilters.com/filtercharger.htm
OVERKILL
$100 Site Donor 2021
Originally Posted By: rpn453
Originally Posted By: OVERK1LL
How is something in FRONT of the MAF and TB going to take away low-end power?
That part of the intake affects the tuning too. The engineers who design the OEM intakes don't make them as small as they do because they're too stupid to realize that bigger is always better.
Interestingly enough, replacing the stock intake tubing on my Mustang did nothing to reduce low-end power, but did increase top-end power.
The engineers have to deal with intake tract NOISE. The reason my Expedition has TWO silencers in the intake tract sure isn't to help with low-end torque production. Both of which are smaller than the factory throttle body.
Removal of these two devices make for an increase in power under full load above 4,000RPM. With no loss of low-end power. It also got MUCH MUCH MUCH louder. The butt-dyno is often confused.
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For lower levels of power output, where most people drive most of the time, the OEM design will often provide more torque and better fuel economy.
Air modulation is performed by the throttle body. This is the last component before the intake. You are trying to tell me that the size of the tubing BEFORE this variable restriction is in some way going to affect how this device functions? The biggest restriction at the "drive around town" power level and throttle position IS the throttle body.
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Of course, the OEM design also incorporates noise reduction, so that may offset the benefits of the smaller diameter intake.
Noise reduction is likely the primary role. You restrict the tract, and make it smooth, and you reduce noise. The fluted airbox breather and the smoothed and reduced diameter throttle body feed tube on my Expedition both do a significant job of reducing noise. An impressive job actually. Removing them increased the under-throttle noise of the engine several-fold.
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Check out the dyno graphs on the K&N website, and you'll find that many, if not most, only show the results above 3500 rpm.
If the factory air system is not adequately able to feed the engine above 3,500RPM under full load, then logic would dictate that replacing it with a freer flowing system would increase power in that area......
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Every design involves compromise, and a CAI usually compromises low-end torque, fuel economy, noise reduction, and filtration efficiency for peak power gains.
Perhaps using the term AFTERMARKET CAI would be more accurate. Most manufacturers utilize some sort of factory cold air induction system. Every vehicle I've ever owned has been factory piped to breath air that comes from outside the engine bay.
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Fly-by-night companies may make fuel economy claims about their intakes because they have nothing to lose, but K&N makes no claims that its products increase fuel economy:
Originally Posted By: K&N
A lot of exaggerated claims are made in the marketplace by products claiming to improve gas mileage. K&N makes no general fuel economy claims, however we encourage you to try our air filter for yourself. Keeping air filter restriction as low as possible can be an important tool, among others, for maintaining high mileage. For more info read what some of our users have to say on the K&N testimonials page.
http://www.knfilters.com/filtercharger.htm
I wouldn't expect a fuel economy gain either. And would ONLY expect a power gain if the factory system was at some point in the engine's power band, a restriction.
Originally Posted By: OVERK1LL
How is something in FRONT of the MAF and TB going to take away low-end power?
That part of the intake affects the tuning too. The engineers who design the OEM intakes don't make them as small as they do because they're too stupid to realize that bigger is always better.
Interestingly enough, replacing the stock intake tubing on my Mustang did nothing to reduce low-end power, but did increase top-end power.
The engineers have to deal with intake tract NOISE. The reason my Expedition has TWO silencers in the intake tract sure isn't to help with low-end torque production. Both of which are smaller than the factory throttle body.
Removal of these two devices make for an increase in power under full load above 4,000RPM. With no loss of low-end power. It also got MUCH MUCH MUCH louder. The butt-dyno is often confused.
Quote:
For lower levels of power output, where most people drive most of the time, the OEM design will often provide more torque and better fuel economy.
Air modulation is performed by the throttle body. This is the last component before the intake. You are trying to tell me that the size of the tubing BEFORE this variable restriction is in some way going to affect how this device functions? The biggest restriction at the "drive around town" power level and throttle position IS the throttle body.
Quote:
Of course, the OEM design also incorporates noise reduction, so that may offset the benefits of the smaller diameter intake.
Noise reduction is likely the primary role. You restrict the tract, and make it smooth, and you reduce noise. The fluted airbox breather and the smoothed and reduced diameter throttle body feed tube on my Expedition both do a significant job of reducing noise. An impressive job actually. Removing them increased the under-throttle noise of the engine several-fold.
Quote:
Check out the dyno graphs on the K&N website, and you'll find that many, if not most, only show the results above 3500 rpm.
If the factory air system is not adequately able to feed the engine above 3,500RPM under full load, then logic would dictate that replacing it with a freer flowing system would increase power in that area......
Quote:
Every design involves compromise, and a CAI usually compromises low-end torque, fuel economy, noise reduction, and filtration efficiency for peak power gains.
Perhaps using the term AFTERMARKET CAI would be more accurate. Most manufacturers utilize some sort of factory cold air induction system. Every vehicle I've ever owned has been factory piped to breath air that comes from outside the engine bay.
Quote:
Fly-by-night companies may make fuel economy claims about their intakes because they have nothing to lose, but K&N makes no claims that its products increase fuel economy:
Originally Posted By: K&N
A lot of exaggerated claims are made in the marketplace by products claiming to improve gas mileage. K&N makes no general fuel economy claims, however we encourage you to try our air filter for yourself. Keeping air filter restriction as low as possible can be an important tool, among others, for maintaining high mileage. For more info read what some of our users have to say on the K&N testimonials page.
http://www.knfilters.com/filtercharger.htm
I wouldn't expect a fuel economy gain either. And would ONLY expect a power gain if the factory system was at some point in the engine's power band, a restriction.
OVERKILL, that reminds me of the noise baffle that the factory had to install on the '03 Cobra intake in order to pass the drive by noise standards.
One simple mod, just removing that rubber baffle, was good for added HP. The baffle is still in my garage somewhere, along with that [censored] stainless factory exhaust.
One simple mod, just removing that rubber baffle, was good for added HP. The baffle is still in my garage somewhere, along with that [censored] stainless factory exhaust.
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What you are saying is true. A larger air intake can sometimes decrease low-end torque because a smaller one at low rpms can have a ram effect and feed air a little better at lower RPM. The smaller air intake will restrict high RPM power more of course. Hot air intakes increase milage not cold air intakes.
OVERKILL
$100 Site Donor 2021
Originally Posted By: mechanicx
What you are saying is true. A larger air intake can sometimes decrease low-end torque because a smaller one at low rpms can have a ram effect and feed air a little better at lower RPM. The smaller air intake will restrict high RPM power more of course. Hot air intakes increase milage not cold air intakes.
How are you going to ram air through an almost closed throttle body?
Maybe WOT at 2,000RPM I could see an increase in "velocity" due to the restricted piping but this is really stretching things.....
The cylinders draw from the plenum. The TB feeds the plenum. Unless you pressurize the plenum via forced induction, anything going on in front of the TB (unless you change the incoming air temperature or skew the MAF reading somehow) is transparent to the plenum.
Now, SOME AFTERMARKET CAI's DO change how the MAF is located in the tubing, which can affect how it reads the incoming air charge. This can, and DOES have an affect on how the engine runs. But this is an issue with the design itself, not simply the diameter of the tubing.
What you are saying is true. A larger air intake can sometimes decrease low-end torque because a smaller one at low rpms can have a ram effect and feed air a little better at lower RPM. The smaller air intake will restrict high RPM power more of course. Hot air intakes increase milage not cold air intakes.
How are you going to ram air through an almost closed throttle body?
Maybe WOT at 2,000RPM I could see an increase in "velocity" due to the restricted piping but this is really stretching things.....
The cylinders draw from the plenum. The TB feeds the plenum. Unless you pressurize the plenum via forced induction, anything going on in front of the TB (unless you change the incoming air temperature or skew the MAF reading somehow) is transparent to the plenum.
Now, SOME AFTERMARKET CAI's DO change how the MAF is located in the tubing, which can affect how it reads the incoming air charge. This can, and DOES have an affect on how the engine runs. But this is an issue with the design itself, not simply the diameter of the tubing.
OVERKILL
$100 Site Donor 2021
This is a dyno run from 2004 for my '87 GT T-Top. This car had a factory Ford CAI on it (3" tubing) into a Pro-M 75mm MAF (stock MAF is 55mm) and a 75mm TB.
Factory, they had a 60mm TB and a restrictive intake. I was told by plenty of people "in the know" that the "huge" Trick-Flow "R" intake I put on this engine, which had runners capable of flowing 350CFM was "too big" and would "kill" low-end torque. That the car would be a turd until at least 3,500RPM.
That the 75mm throttle body would also "kill" the car.
The camshaft is a trick-flow "Stage 1", which "comes on" about 3,000RPM.
Note that it makes 260lb-ft of torque to the rear wheels at 3,100RPM, which is where the pull started.
Factory, they had a 60mm TB and a restrictive intake. I was told by plenty of people "in the know" that the "huge" Trick-Flow "R" intake I put on this engine, which had runners capable of flowing 350CFM was "too big" and would "kill" low-end torque. That the car would be a turd until at least 3,500RPM.
That the 75mm throttle body would also "kill" the car.
The camshaft is a trick-flow "Stage 1", which "comes on" about 3,000RPM.
Note that it makes 260lb-ft of torque to the rear wheels at 3,100RPM, which is where the pull started.
It will give you god like HP only if you install it behind the rad, hot air moves faster. Also only use K & N they are the bestest ever (is that even a word?). Trust me I've seen it all! I know from..... LMAO!!!..... Experience.
whom ever said the small tube tunnel ram thing needs a lesson on physics and not advertisements. The engine creates a low pressure area and the high pressure area (atmospheric pressure) moves into the engine. How is a straw equal to a fire hose for restriction at any flow rate?
I have heard of ppl claiming to have gained moderate MPG's and so they think/feel power. These ppl are Not hindered idiots just your normal everyday Joe. I have no statistical data just hear say. I also might add, they did install actual boxed in cold air intake system.
whom ever said the small tube tunnel ram thing needs a lesson on physics and not advertisements. The engine creates a low pressure area and the high pressure area (atmospheric pressure) moves into the engine. How is a straw equal to a fire hose for restriction at any flow rate?
I have heard of ppl claiming to have gained moderate MPG's and so they think/feel power. These ppl are Not hindered idiots just your normal everyday Joe. I have no statistical data just hear say. I also might add, they did install actual boxed in cold air intake system.
This is pretty interesting. Thanks. I wasn't looking for performance (I drive like grandma trying to save gas to a reasonable extent). I've already beaten the EPA figures easily with 27 mpg on the highway, and the truck never gets below 21 around town (my fullsize Dodge got 21 best ever highway and worst was 16 around town). The truck usually sees 25 mpg highway and 24 driving back and forth to work. I should probably be satisfied with those numbers, but I thought a 4 cyl could do better. BTW it is 2.9 4 cyl automatic ext cab 2WD.
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