Aftermarket Intake Gas Millage Question
Aftermarket Intake Gas Millage Question
(OP)
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.





RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
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RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
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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RE: Aftermarket Intake Gas Millage Question
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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RE: Aftermarket Intake Gas Millage Question
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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RE: Aftermarket Intake Gas Millage Question
Dan - Owner

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RE: Aftermarket Intake Gas Millage Question
Cheers
Greg Locock
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RE: Aftermarket Intake Gas Millage Question
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

http://www.Hi-TecDesigns.com
RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
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RE: Aftermarket Intake Gas Millage Question
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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RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
thread71-214125: air filter vs fuel economy (tricky question?)
thread71-252102: air filter vs fuel economy - controlled test results
RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
http://www.calsci.com/motorcycleinfo/Airboxes.html
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.
RE: Aftermarket Intake Gas Millage Question
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.
RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
RE: Aftermarket Intake Gas Millage Question
- Steve
RE: Aftermarket Intake Gas Millage Question
Notwithstanding some of the points made in recent posts which I have no quibble with, some engines benefit from more air, namely Diesels. The amount of fuel added depends on your foot.
I put an aftermarket intake on a IDI diesel engine once and it improved the fuel mileage when I drove it decently, but hurt it when I mashed on it a lot. And I did both at times. It was up to me, but when I wanted to, I got better mileage than with the original restrictive manifold. When I needed it, it was nice to have that extra power that the additonal air allowed me to put the fuel to.
rmw
RE: Aftermarket Intake Gas Millage Question
NOOOOOOO you are not getting it.
The total combination of the throttle restriction and whatever restriction exists upstream will total out to be 100.0000000% the same, such that exactly the same amount of air goes into the engine, such that the output power precisely matches what's demanded to run the car down the road. Since air/fuel ratio is held constant, so will the fuel delivery.
Do you understand that:
8 + 2 = 10
9 + 1 = 10
7 + 3 = 10
Same result different ways.
Stock restriction (call it "2" for argument's sake) requires throttle restriction "8" to get total restriction "10".
Less restriction (call it "1") means more throttle restriction (call it "9") but the total is still "10".
By the way, diesels are a different ball game because they are operating unthrottled.