[K320]

I just has one month running one and I believe my mileage drop a little.
Good response from throttle and sounds a little different.
What to know is this is good for our cars or if it is not (my last car has an issue with the maf).
I saw a review of a guy in youtube on which he runs his car with 32onz of gas in eco mode, change the air filter to KN and restart the process. His mileage drop. Here is : http://www.youtube.com/watch?v=rKWIuOQ7dAo

Want to know your impressions.

[xantdieselx]

Originally Posted by Kendroz

I just has one month running one and I believe my mileage drop a little.
Good response from throttle and sounds a little different.
What to know is this is good for our cars or if it is not (my last car has an issue with the maf).
I saw a review of a guy in youtube on which he runs his car with 32onz of gas in eco mode, change the air filter to KN and restart the process. His mileage drop. Here is : http://www.youtube.com/watch?v=rKWIuOQ7dAo

Want to know your impressions.

I used to swear by them with mostly NA cars. I put one in my last car an 11' GTI but in addition to the mileage drop, you could definitely tell low end torque was missing.

Most people will tell you that the stock air box with a paper filter is more than adequate for even a mildly modded car.

[K320]

Originally Posted by xantdieselx

I used to swear by them with mostly NA cars. I put one in my last car an 11' GTI but in addition to the mileage drop, you could definitely tell low end torque was missing.

Most people will tell you that the stock air box with a paper filter is more than adequate for even a mildly modded car.

My suspictions were correct.
Thank's for your reply.

[Rick4345]

I have had them in all my cars and motorcycles. My 328i gets about 38 mpg on average.

[Efthreeoh]

I used K&N's in all my vehicles, but changed them all out a few years ago. I've never seen any increase in fuel mileage nor any discernible performance increase. A waste of money IMO.

[DeltaFX1942]

After two cars with K&Ns, I never really saw a real boost in performance but did lose out on almost $100 on those filters. MPGs stayed consistent or dipped a little.

[Dog Face Pony Soldier]

I've had nothing but positive experiences with using high performance drop-in filters. Not sure what the logic is behind the theory of a high-flow drop-in filter causing a decrease in performance or fuel milage.

[Kafkaesque328]

Me neither, I ran an aFe Pro Dry S drop-in with Stage 1 tune on my GTI for years and I preferred it over the SRI I had. When listing the car for sale I put the OEM paper filter back in and drove back and forth to work for a few days, same commute and averaged about 1.5mpg less consistently. Trottle response was not as good as before either. Less turbo noise. That was on a tuned car though. Stock, I don't know what difference it makes. Never been a fan of oiled filters personally

[mshanno1]

waste of money...

I read somewhere on here that testing concluded that the stock airbox is not restrictive for the stock power that the car is making.

[Efthreeoh]

Originally Posted by Kafkaesque320

Me neither, I ran an aFe Pro Dry S drop-in with Stage 1 tune on my GTI for years and I preferred it over the SRI I had. When listing the car for sale I put the OEM paper filter back in and drove back and forth to work for a few days, same commute and averaged about 1.5mpg less consistently. Trottle response was not as good as before either. Less turbo noise. That was on a tuned car though. Stock, I don't know what difference it makes. Never been a fan of oiled filters personally

I can't speak to the filters you've mentioned, but I keep very strict fuel mileage records for all my vehicles, for every tank fill up, over hundreds of thousands of miles. In every case I noted when I changed the air filter to a K&N and then looked at the fuel usage data for the next 10,000 miles (just to use a number for discussion sake) and I've not seen any long term average increase (or decrease) trend. The variability of each tankful MPG average can easily be in the 1.5 MPG range. And like you I see no advantage to an oiled filter, considering the possibility of misuse leading to damage of the sensors in the intake system.

[vader1]

I have used K&N cones in modified cars with custom applications and don't have anything to compare them to because the applications were going from NA to FI.

I have used the drop in replacements in stock cars, an NA Toyota Highlander and a turbocharged Subaru.

I never could "feel" any performance difference with either. I will say, however, that each car had about a 5% bump in mileage or about 1 mpg after going K&N. I record my mileage religiously each tank, and it was not imagined, but basically I just bought them because they were reuasable and just a few bucks more than a stock filter. Cleaning and re-oiling is easy.

My 5% mileage bump should be taken with a grain of salt because there are variables you can not account for, like traffic conditions and temperature. But for example, what I noticed that going several winters on stock filter would get me tanks in the 20-22 mpg range, then switching the tanks went to 21-23.5% in the winter. They were of course different winters but approximately the same basic conditions and driving style. The "summer" tanks had similar improvements. Going from the 24-25mpg range to 25 to as high as 27mpg range. It aint a perfect measurement, but the only variable I could most definitely account for was the K&N.

If you don't believe any performance/efficiency benefit, they will pay for themselves by pretty much just cleaning it well and reusing it once.

[momo3605]

Originally Posted by Rick4345

I have had them in all my cars and motorcycles. My 328i gets about 38 mpg on average.

how!? I can barely get 30mpg cruising at 75

[Rick4345]

Originally Posted by momo3605

how!? I can barely get 30mpg cruising at 75

I'm not real sure. I just try to do things like accelerate smooth and things like coasting up to a stop light. I pretty much stick to the speed limit. I live in a rural area, so I don't have a lot of stop and go driving. I've put a K&N in all my vehicles as soon as I can. I even have one in my work car. It's a 2012 Chevrolet Caprice with a 6.0 liter. Maybe it's all a mental thing. I can tell you that I ran my last car at work up to 251,000 and had it for six years with the same K&N in it also.

[TurboM]

Originally Posted by momo3605

how!? I can barely get 30mpg cruising at 75

Same here...

28-29mpg 50/50 city/highway

[reedo302]

I average 27mpg with 70% freeway doing 65-80mph. I have the aFe filter in mine. I did a road trip down I-35 to Des Moines doing 82mph average and got 33mpg. When I did another road trip doing 62mph avg, I was at 40mpg.
I'd be curious to see what happens with a long range trip, but in all honesty, I noticed no difference in performance between the stock paper and the aFe. Once I get software, I'm sure it'll be more pertinent.

[casualDIYer]

Unless there was a significant change I don't think you'd notice any difference at all. I've used one in the past with a Korean car and didn't see a difference. As one poster noted, conditions can change mileage. You'd really need two identical cars tested at the exact same time to have a 'true' test.

[F30JB]

I had the K&N filter on for a few thousands miles and noticed no difference in mpg versus stock paper filter. Sounds is about the same as well.

[Kafkaesque328]

Originally Posted by F30JB

I had the K&N filter on for a few thousands miles and noticed no difference in mpg versus stock paper filter. Sounds is about the same as well.

Good to know. Only reason Id use one is for more noise since this car is so quiet. I couldn't care less about 5% MPG increase (alleged) since this car already get's fantastic mileage.

[f30kid]

I just put one in last week the K&N high performance one - and i notice a big difference the car has came alive. Sound is way different and sounds great.

[Phiwee]

Almost sounds like a bov? woosh woosh

[Kafkaesque328]

Been thinking a little about getting one of these, mainly out of boredom and because the engine is so quiet. The AFE I had on the GTI made the wastegate dump and turbo sounds more pronounced which was cool. Seemed to increase throttle response a hair at tip in as well. Who knows. Since I'm tuned and pulling in more air it might do a little more good vs. stock

I am not into oiled filters so I'd get this one. But man, $70 for this thing? As I said, I was happy with the aFe in the GTI, even if just sonically, and I have no illusions about mileage or performance but $70 is kind of a rip.

http://afepower.com/shop/details_new...0L&&brandID=59

[BeachsideF30]

Originally Posted by Kafkaesque320

Been thinking a little about getting one of these, mainly out of boredom and because the engine is so quiet. The AFE I had on the GTI made the wastegate dump and turbo sounds more pronounced which was cool. Seemed to increase throttle response a hair at tip in as well. Who knows. Since I'm tuned and pulling in more air it might do a little more good vs. stock

I am not into oiled filters so I'd get this one. But man, $70 for this thing? As I said, I was happy with the aFe in the GTI, even if just sonically, and I have no illusions about mileage or performance but $70 is kind of a rip.

http://afepower.com/shop/details_new...0L&&brandID=59

Any consideration to trying the pipercross foam filter? I used one in my e92 euro box setup.