CAI performance

[Kennyredline]

Are there any situations where installing a CAI would affect gas mileage? I installed one in my '03 Jetta 1.8T a few months ago, and my gas mileage has gone down by 40-45%. It could be something else of course, but it seems very co-incidental, and I don't want to switch it back out until I'm sure the CAI is causing my bad mileage.
Thanks for feedback.

[T-Dubbs]

aftermarket intakes on jettas usually kill power.
so its very possible

[GQBalla]

just put back on the stock intake and see what happens

[Kennyredline]

Originally posted by T-Dubbs
aftermarket intakes on jettas usually kill power.
so its very possible
Well, no, the power is great, but my mileage has gone to shit. I'm talking about highway mileage too, not going really fast, maybe 120kph...

[T-Dubbs]

Originally posted by Kennyredline

Well, no, the power is great, but my mileage has gone to shit. I'm talking about highway mileage too, not going really fast, maybe 120kph...

haha you think so eh?
do a dyno, before and after with CAI
CAI on 1.8t is only for sound.
CAI are pretty useless for Jetta's

i agree with above
put on the oem airbox, and see if that fixes your problem

[Kennyredline]

Ah well I just put the old stuff back and went for drive out to Cochrane, 87km or so , and the gas gauge moved a lot more like it used to. What a crock, all I heard was how great things were gonna be with the CAI, what a fucking waste of time and money.:banghead:

[Cos]

More air = more fuel.

[T-Dubbs]

Originally posted by Kennyredline
Ah well I just put the old stuff back and went for drive out to Cochrane, 87km or so , and the gas gauge moved a lot more like it used to. What a crock, all I heard was how great things were gonna be with the CAI, what a fucking waste of time and money.:banghead:
ya its a bitch!
best to do research on parts before you waste money on them

[Kennyredline]

Originally posted by T-Dubbs

ya its a bitch!
best to do research on parts before you waste money on them
I TOTALLY DID!!!! lol
Even the website I got the part from said it would save gas, and a bunch of other people said that too, although I wondered how that would actually work...
Anyway, FS one CAI for fourth gen. Jettas. $100.

[Mr_ET]

You know when you modify a car, especially a turbo one, tuning is key.

You cannot expect to slap on a part with the computer tuned for a stock airbox and expect that it will make optimum power and have the best gas milleage.

Computers are too intelligent now, they will know you changed something through the map of maf and will self correct fuel trim. This is probably what caused the milleage to go down.

I would bet that if you got it tuned for the CAI, it would make more power and probably get better milleage than it did untuned.

With that said, if it makes more power and sucks in more air, it will need more fuel to keep the engine happy and gas milleage will suffer.

[T-Dubbs]

Originally posted by Kennyredline

I TOTALLY DID!!!! lol
Even the website I got the part from said it would save gas, and a bunch of other people said that too, although I wondered how that would actually work...
Anyway, FS one CAI for fourth gen. Jettas. $100.
i have one in my garage that i bought for my 03 jetta, but it just sits in my shelf now. lesson learnt:thumbsdow