K&N Air Filter vs MPG...is this a fluke?

[Radio]

Originally Posted by MREZ

The computer will adjust for the increased airflow and you will soon see the MPG back to reality.

Mike

I wonder how to keep the computer in this delightfully unreal state??
Shouldn't the computer have made these adjustments "on the fly" as soon as the airflow changed?

[MREZ]

I think it takes 1 or 2 drive cycles to make the adjustments.This is what I have been told anyway.I have also been told you will still see HP gains at full throttle because of the extra airflow

[acadianbob]

Man I would yank that K&N. There is no free lunch on air flow. IMO a K&N will let in more microscopic particles that cause wear on your engine; particles you can't see. And for what benefit? Claims of increased horsepower and gas mileage are grossly exaggerated. If it was that easy, why doesn't the factory do it? And the K&N needs maintenance; cleaning, re-oiling . . And speaking from experience, I once used K&N on an autocross car looking for more power, it bought me nothing in lap times or fuel mileage. Yanked it.

[hunt4240dw]

Radio,
I have a Fram Airhog which is the same as the K&N. I saw about a 1 mpg increase and a lot better throttle response. Did the air temp warm up from the week before? If so, you always get better mpg in warmer weather.

For campingsince68, have you thought a ECU custom tune? I have one that totally improves my daily and towing drives. It can help with shifting by removing most of the GM torque management and timing tables better than the tune boxes. I got mine from MGSCustom Tunes in Canada. It cost me $400 for a life time of tunes. If I sell my truck, they will even send a tune for the new truck. There is also Justin at BlackBear Preformance that does a really good job.

David

[Radio]

Originally Posted by acadianbob

Claims of increased horsepower and gas mileage are grossly exaggerated.

Yep, they are. As far as MPG are concerned my jury is still out. I have no claim in this (except my $45 I paid for the filter ) and no ego involved. As a test engineer anything I can't measure is just an opinion. In two more tanks (two more measurements) then I can say for fact what's going on here.

As for horse power and throttle response I have no way to measure either. But right now, on this particular truck, with my driving needs and in this weather...things sure look good for the K&N as far as MPG, which I can measure with some accuracy.

A couple more weeks guys, and we'll all know.

[Radio]

OK, I jumped the gun a little bit and didn't go the usual 340 miles or so. Filled up at 279.9 miles with 18.578 gallons which calculates out to 15.06 MPG.

What the heck is that all about? What is going on with this truck? I can't recall any appreciable difference in driving style or weather conditions. It occurred to me that I should reset the powertrain computer?

Maybe somebody siphoned off a gallon or two while I was parked at the shopping center where I meet my carpool.

I have no clue. Another tank or two and we'll see.

[MREZ]

The first tank of fuel with the K&N I was driving around yelling wooo hoo then reality set in cant say we didnt tell you

[slpybeartx]

Just a question, Radio.... why would you use a different gas station to fill up each time for your test? (I think you mentioned this earlier.)

For MPG calcs, I believe you need to use not only the same station, but also the same exact pump for all before and after fuelings to calculate mileage inbetween... and if you want to run several tanks, I think you need to use same scenario for all tanks considered.

Interesting results... kinda matches what i found out with my Fram Air Hog filter... I have the factory equiped Z-71 pkg, that included an oversized airfilter. I saw no difference in changing air filters... from stock to Air hog... I believe the larger airfilter already gave the truck the benefit of the increased airflow... so filter media did not make a further difference.

So far, I have been happiest with the Active Fuel Management engine as the biggest bang for the buck. I previously had a 2WD truck with the same setup, (3.23 rear end vs. 3.73 I think was other diff). My old truck woudl knock down 20-21 mpg pretty regularly on the highway. My new truck does 19-20 on the highway with the 4WD and higher rear end gears... so very happy. Especially with the improved towing capability....

Please keep us posted!

[Radio]

Originally Posted by slpybeartx

Just a question, Radio.... why would you use a different gas station to fill up each time for your test? (I think you mentioned this earlier.)

For MPG calcs, I believe you need to use not only the same station, but also the same exact pump for all before and after fuelings to calculate mileage inbetween...

Well...you need to get gas where you need gas! On the second tank I did luck up and get the same staion and pump. However, prior to this I always was getting 16.4 mpg or close to it no matter where I filled up. Will get another tank this weekend, and the experiment goes on. Will try for the same pump again.

[Radio]

OK...my latest mesured MPG was 17.4 which is 1 MPG up from the life long average of 16.4. I bet this continues to fluctuate, but a gain of 1 MPG would actually be what I expect to get.

We'll continue to measure.