View Full Version : Air Intake – Impact on Fuel Economy


JanusFive
02-16-2004, 05:54 PM
Me again!

While I did not order the optional air intake enhancement, I’ve been thinking about maybe doing this in the future.

I drive (until my xB comes in) a 2000 VW Beetle TDI, which is a TurboDiesel with 90hp, so as you might imagine, I’m not used to, or really wanting a LOT of power. But for whatever reason, the enhanced air intake intrigues me enough for me to keep it in mind.

The TDI got insane fuel economy – 49MPG highway. My question, therefor, is this: what impact, if any, does the cold air intake have on fuel mileage? Does it make the engine drink gas faster, or does it help the engine become more efficient? I’ve looked everywhere for an answer, but so far, no dice! I prize efficiency over power for the most part, so I’d not want to do anything to the engine that’d make it more thirsty.

Anyone know? = 8)

Thanks!
Larry

iy0ga
02-16-2004, 06:05 PM
i soppose it will make it more thirsty bc intake is supposed to boost up your hp. hp=more gas :lol:

jackmott
02-16-2004, 06:52 PM
i soppose it will make it more thirsty bc intake is supposed to boost up your hp. hp=more gas :lol:

no.

it will probably have no measurable difference, but it should get better milage. The engine needs to do less work to pull in the same volume of air

CBSIMONSEZ
02-16-2004, 08:07 PM
No not exactly. I have had my intake on my NEON for over 3 years now. I can tell you that i had better gas mileage BEFORE i install the CAI. With the CAI installed, my fuel consumption went up, not a lot, just ever so slightly, which stands to reason, because of the induction of more air. More air+more fuel=more power, which i have noticed on my NEON, considerably more power, esp on the lower end.

Will this stop me from getting an intake for my xB, not at all. I know from first hand experience that allowing the engine to breath, gives better performance. I plan on having mine here at the house waiting for my xB, among other things.

BlueBox
02-16-2004, 08:24 PM
from my personal experience, the mileage has dropped after intake installation.

running on stock , i use to get about 29mpg...now i get about 26/27mpg with my CAI.

scion_sales
02-16-2004, 08:38 PM
We have been told at our dealership to use the figure of 3-5% reduction in MPG after the installation of the CAI.

That sounds about right after reading everyone else's posts.

Mark aka Scion Sales

jackmott
02-16-2004, 09:05 PM
no, it does not stand to reason.

to accelerate at the same rate you would use less throttle than before, hence there is no more air going into the engine.

I would suggest either the change in mileage was due to your right foot getting more active, or because the intake was causing turbulence at the maf sensor. (not an uncommon occurance)



No not exactly. I have had my intake on my NEON for over 3 years now. I can tell you that i had better gas mileage BEFORE i install the CAI. With the CAI installed, my fuel consumption went up, not a lot, just ever so slightly, which stands to reason, because of the induction of more air. More air+more fuel=more power, which i have noticed on my NEON, considerably more power, esp on the lower end.

Will this stop me from getting an intake for my xB, not at all. I know from first hand experience that allowing the engine to breath, gives better performance. I plan on having mine here at the house waiting for my xB, among other things.

CBSIMONSEZ
02-16-2004, 09:36 PM
Ok, so you mean to tell me that with the resinator box, with all its baffles, and the paper air filter in place, the engine is trying to breath with all these restrictions, and freeing that up does not allow for better air flow, which in turn will allow for more fuel consumption at that given point? Right :wink:

BigBadWolf
02-16-2004, 09:54 PM
Speaking from personal experience.
CAI does give you better gas mileage. Since the engine uses less energy to pull in the same amount of air.
Example: B4 CAI, while traveling at 60MPH. Your engine was revving at 2855RPM.
After CAI, your engine will now rev at about 2805RPM traveling at the same speed.

I have a CAI, header, exhaust and a FlowMaster Cat setup. This setup makes my engine breath a whole lot easier. (Louder too) With the extra boost in HP, i now tend to drive much faster. This reduces my mileage to about 19 MPG. While before the install, i was getting about the same MPG, but it drive much slower and with much less peppiness.

But, if your driving pattern remain the same as before the install, (Acceleration rate, top speed...etc) you "WILL" definitely achieve better gas mileage.

BTW: This is one of the reason i have choice this vehicle, so i can drive much slower...
I now drive a Suzuki Grand Vitara, I was driving a 2000 528I Sport before this. (I was single then)

Radiodude
02-17-2004, 10:53 AM
I agree with some of the other guys YES in THEORY a CAI will ultimatley result in better performance and better gas milage... 100% exactly sure of how much of either, its anyones guess.

BUT the problem lies if you can tell the difference in power.. odds are your gonna wonna use it and hammer more so than before.

If, and a BIG if, you can resist that urge most of the time to rev it odds are the CAI will pay for itself in gas and pleasure over the years.

JanusFive
02-17-2004, 12:09 PM
Ah, to resist temptation and save gas... :oops:

Thanks for all your help, everyone! I think I'll add one a little later!

Larry