Tim94gt

iTrader: (1)

That's not an unreasonable expectation, most people do notice a small increase in MPG's with a CAI. I know I did.

Have you changed your driving habits since installing it? Some people like to hear the intake and end up on the throttle more than normal.

Is the truck tuned? If not, I'd get a tune over wideband.

KC_kid

iTrader: (5)

My new spark plugs have maybe 10,000 miles on them, I don't know what they look like. The originals that I took out looked fine, even with 135k + miles on them, they could have kept going, at least by the looks of them.

I did change my driving habits initially, because I did enjoy the sound of the intake. But after awhile I changed them back to more conservative, attempting to get my mileage back in line. And my highway driving habits did not change, which is really were I'm seeing the changes. Were I live, a city drive one day might get you 7 mpg and the next day you get 14mpg, so I try not judge based on city driving.

I have a Nelson 91 octane mail order tune and he was aware of the K&N intake when I ordered the tune.

I'm wondering if this particular truck is picky with it's incoming air and it could be tuned around. I've read where tuners say that every engine is different... And with the same results on two separate instances, people, driving styles, life of the engine, etc... I think it's the engine, but don't know how to fix it.

KC_kid

iTrader: (5)

I put back on the stock airbox tonight and went on a quick test drive. This was by no means a scientific experiment, I went 3 out of my normal 3.5 mile drive to the office on the frontage road, then came back on the interstate. It was a noticeable change. Obviously quieter, but I've been between 10.8-11.5 on my drive to work as of late, this test drive I was at 13.5mpg after 3 miles. The Scangauge gives me instantaneous MPG and trip MPG, so that's how I'm reading it.

I think this truck likes the airflow from the stock box, not sure why, maybe the K&N is TOO free flowing, if that's possible. I noticed it idled smoother at the lights, which I've been wondering why I have a slight stumble/shutter/flutter thing every once in a while at stoplights, and I think now it was that K&N causing it. It pulled better at low RPM also, getting onto the interstate.

I'm looking forward to seeing how this pans out, I should have taken this thing off months ago...
Oh and I have been running new O2's this week and noticed no change.

pasadenaman

iTrader: (3)

Good going on getting your mpgs back

KC_kid

iTrader: (5)

Actually yes, I think so. This truck gets driven so little that it's hard to get a good handle on where the MPGs are sitting. I only have a 3.5 mile drive to work each way so I barely get to operating temp before I turn it off and it takes ~3 weeks to get through a tank. But for the past 4months I have religously watched my Scangauge instant & trip MPG back and forth to work, to try to get an average. With the FIPK I was consistenly around 11mpg, usually 10.8 area. Now I'm consistently in the 13's. The longer my in town trip, the higher my MPG will go, it went up to 15 when I travelled about 10 miles in town this week. But on the other hand, if I drive home very "spirited", I see the old mileage again, right at 11. I have not had a chance to measure highway mileage.

The comment I made about it idling smoother is still up in the air. That wasn't a consitent characteristic anyway so I can't confirm why that's happening or if it's actually gone.

KC_kid

iTrader: (5)

I just filled up, 18 gallons. Same pump, last 2 fill ups have been 19.4 & 21.8 gallons, calculated 11.9 and 11.3 MPG. This 18 gallons I calculated 13.1 mpg, same driving style, back & forth to work. I took off the FIPK during this tank, I would guess it was 40% with K&N, 60% with stock airbox.