Is it a myth that your cars fuel economy will be improved with an aftermarket intake system. I know in most cases it decreases due to the driver putting the pedal to the floor more due to the sound of the intake sucking in and the increased throttle response. But, I'm saying if your a conservative driver and you put an aftermarket intake on your car and remain a fairly conservative drive will your fuel economy increase like companies claim? And to be specific here I'm talking about a Short Ram and not a cold air.
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Aftermarket Intake Gas Millage Question 1
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With that point you could argue the fact that why don't manufactures make their cars faster? Theres standards and such that these cars are engineered to and requirements they must meet when they come of the assembly line that makes those types of things very hard for them in the first place. Which is why there is an aftermarket for this type of thing.
No, there is no need for cars to go faster.
However, there is a CAFE law that requires that cars achieve a certain mileage. Because of all the smog controls and whatnot, corporate gas mileage is constantly under achieving, and if a simple intake change was all that was needed, all the car companies will jump at the change, just to bring up the average mileage so that they can easily meet the requirements of the law.
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FAQ731-376
However, there is a CAFE law that requires that cars achieve a certain mileage. Because of all the smog controls and whatnot, corporate gas mileage is constantly under achieving, and if a simple intake change was all that was needed, all the car companies will jump at the change, just to bring up the average mileage so that they can easily meet the requirements of the law.
TTFN
FAQ731-376
patprimmer
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If you use an after market inlet that is much more restrictive you will see a fuel economy increase that is somewhat proportional to the power decrease.
Otherwise, how can an after market inlet improve fuel economy. Do the people making the claim explian the mechanism by which it occurs.
Regards
Pat
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Otherwise, how can an after market inlet improve fuel economy. Do the people making the claim explian the mechanism by which it occurs.
Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
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GregLocock
Automotive
"If you use an after market inlet that is much more restrictive you will see a fuel economy increase that is somewhat proportional to the power decrease."
I think this known as the "put a sock in it" argument.
If you think about the intake system as a long tube with various restrictions in it, it becomes remarkably hard to explain why any restriction in that tube will be better, or worse, than any other restriction, for fuel consumption. This does not apply at full throttle of course.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
I think this known as the "put a sock in it" argument.
If you think about the intake system as a long tube with various restrictions in it, it becomes remarkably hard to explain why any restriction in that tube will be better, or worse, than any other restriction, for fuel consumption. This does not apply at full throttle of course.
Cheers
Greg Locock
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MacGyverS2000
Electrical
The stock airbox is designed with reduced acoustics in mind... since the aftermarket world is not restricted with this, there is power to be had.
Dan - Owner
Dan - Owner
GregLocock
Automotive
Yup, but not economy.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
MacGyverS2000
Electrical
Greg,
Would you agree that at the extremes, where the airbox provides the heaviest restriction to airflow, the aftermarket piece would provide for a better economy?
Dan - Owner
Would you agree that at the extremes, where the airbox provides the heaviest restriction to airflow, the aftermarket piece would provide for a better economy?
Dan - Owner
patprimmer
New member
The fuel injection system is calibrated to provide the correct amount of fuel for the air.
The throttle normally controls the air.
If the inlet is more restrictive than the throttle at WOT, the inlet controls the air rather than the throttle controlling it once the throttle goes past the point where inlet and throttle are equal, well to a point.
High flow or cold air induction adds power at WOT, not fuel economy. At cruise it makes no difference as the throttle is the real restriction.
Regards
Pat
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The throttle normally controls the air.
If the inlet is more restrictive than the throttle at WOT, the inlet controls the air rather than the throttle controlling it once the throttle goes past the point where inlet and throttle are equal, well to a point.
High flow or cold air induction adds power at WOT, not fuel economy. At cruise it makes no difference as the throttle is the real restriction.
Regards
Pat
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With modern fuel injected vehicles you have sensors that take calculations on how much air and the temperature of that air is going into the engine. Along with how much fuel is not being used by the engine on the exhaust side. The computer will only ever send as much fuel to the engine as much air is being sent to keep the air-fuel ratio within its design. More air means more fuel. Very simple.
probably No economy impact, but I think in some cases air inlet (air box, air filter case, etc) tuning has been used to correct or at least minimize dips in the power curve, even of F-Injected engines.
plus a few articles by Kevin Cameron of Cycle World.
Then there's the situation where the inlet "restriction" is a nice long intake runner of an appropriate size, whose positive inertia effects add more horsepressure than the few inches of water pressure drop cost compared to an oversized stub.
plus a few articles by Kevin Cameron of Cycle World.
Then there's the situation where the inlet "restriction" is a nice long intake runner of an appropriate size, whose positive inertia effects add more horsepressure than the few inches of water pressure drop cost compared to an oversized stub.
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BrianPetersen
Mechanical
"For the same engine output power, if you could make the engine more efficient (less air restriction on the input), wouldn't the input power be less?"
No, because it takes a fixed amount of power and therefore a fixed amount of intake air to drive the car down the road under conditions that are identical with the only difference being your hypothetical low-restriction intake. Except at top speed or maximum hill-climb or acceleration - which ordinarily are a very small part of normal driving to the point of being insignificant - whatever intake restriction isn't achieved by the air intake ductwork, will be made up by closing the throttle a little more. Result ... No difference.
No, because it takes a fixed amount of power and therefore a fixed amount of intake air to drive the car down the road under conditions that are identical with the only difference being your hypothetical low-restriction intake. Except at top speed or maximum hill-climb or acceleration - which ordinarily are a very small part of normal driving to the point of being insignificant - whatever intake restriction isn't achieved by the air intake ductwork, will be made up by closing the throttle a little more. Result ... No difference.
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