K&N drop in = less MPG?

[JimsSpeed3]

It seems like my MPG has gone down since I bought a K&N drop in filter for the stock airbox. My first two tanks were about 25 mpg with mostly in town driving, my normal pattern. Then I got the K&N and my MPG has been about 23 MPG since with the same driving pattern. This morning I put the stock air filter back in to see how my MPG is the next couple of tanks. I bought the 3 because the 12 MPG my Hemi Ram get's was really starting to add up. If the K&N actually hurts MPG, I'm going to leave it out. I'm sure I was lucky if I got another 1-2 HP from it and the drop in MPG isn't worth it for what I bought the car for. Anyone else experience this?
Jim

 

[krimsonviper]

give it a minute, it'll start saving you some gas at about 100 miles or so,(dunno) go figure

 

[Breeegz]

ECU relearning perhaps?

I never paid attention in my P5 when I had the drop-in. Didn't have the car long enough without the K&N.

 

[JimsSpeed3]

I only had two tanks ran through my 3 when I switched to the K&N. I'm going to get a better baseline with the stock filter on MPG, about 3-4 tanks then I'll put the K&N filter back in. One note: The K&N filter actually has been proven to lose power and MPG on Hemi Ram trucks. I put one in my Ram before I installed a CAI and I lost 2 mpg. Other Dodge members dynoed a K&N and the stock filter, the K&N lost 5 hp and 5 tq over the stock filter. When I put the stock filter back in, my mpg went back up. I wonder if the same thing is happening here? Anyone ever dyno test a K&N drop in filter vs stock?
Jim

 

[krimsonviper]

I only had two tanks ran through my 3 when I switched to the K&N. I'm going to get a better baseline with the stock filter on MPG, about 3-4 tanks then I'll put the K&N filter back in. One note: The K&N filter actually has been proven to lose power and MPG on Hemi Ram trucks. I put one in my Ram before I installed a CAI and I lost 2 mpg. Other Dodge members dynoed a K&N and the stock filter, the K&N lost 5 hp and 5 tq over the stock filter. When I put the stock filter back in, my mpg went back up. I wonder if the same thing is happening here? Anyone ever dyno test a K&N drop in filter vs stock?
Jim

how long were those ram owners actually driving around with them in? you do lose a bit in the beginning, but after the filter collects some dust, it'll be all good. I dont know why it needs to collect some dust, but it just does.I just remembered dropping one in my 240 and she used to get 24MPG(never had time to keep up maintenance, hence i got a 3) and it jumped up to 29/30 range. I'd imagine if i kept up maintenace, it would have seen higher MPG, but i'll never kno, i sold my baby(doh)

 

[nate0123]

who said it would improve mileage?

more air (the goal of a freer-flowing intake, yes?) requires more fuel to maintain the proper AFRs, yielding slightly more power, but slightly less fuel economy

 

[JimsSpeed3]

who said it would improve mileage?

more air (the goal of a freer-flowing intake, yes?) requires more fuel to maintain the proper AFRs, yielding slightly more power, but slightly less fuel economy

I thought K&N use to claim an increase in MPG along with more power. I just checked their website and the MPG claim is now gone. I agree that more air in will actually decrease MPG as the MAF see's the air flow increase and adds more fuel. But the slight increase in power may help MPG because it'll take a little less pedal to achieve speed. I guess not in my case.
Jim

 

[iracemine]

I would think more air means more fuel, so less throtle. maby you are experimenting with the throtle a littile. try going 10 tanks with each.

 

[krimsonviper]

maybe my MPG gain was due to the it being a new air filter and my old one jus needed to be changed, but i doubt it, the airfilter used to be a cone filter on my 240 and i didnt want that one cause that one needed to be changed(chair)