How much horsepower will a drop in K&N filter give me?

25

Asked by Apr 15, 2008 at 12:43 PM about the 2008 Nissan Altima Coupe 3.5 SE

Question type: Car Customization

16 Answers

30

I put a K&N on my truck I also removed the screen before the air filter box and don't forget to remove the positive cable for 5-mins so the computer can reset and re-learn the new air-fuel mixture. You will hear and feel the difference. Remember more air means more gas and less miles per gallon! (OUCH!)

2 people found this helpful.
135

first of all you wont notice much if any difference; seat of pants difference takes more than a 2hp increase. secondlyin response to the guy above dont you think engineers spend countless hours do making sure that the stock paper element isnt restrictive and how will there be more sound? thirdly it will use the same or less amount of gas until you floor it all the time naturally the milage is most dependant on the driver

3 people found this helpful.
295

yea more air means more gas, but your only going to get more air if your accelerating harder. The K&N filters simply make air flow less restrictive, and thus more efficient. You will see nothing but improvement. However, k&n gets expensive. A k&n for my car costs about 180 plus shipping, and i got one off ebay, just a s good, for 70 shipped

55

1 - 3 hp max, and it does flow in lots more air, but it also flows in lots more particles. Stick with the factory style air filters, unless you're getting a decent WAI or CAI.

3 people found this helpful.
40

Paper filters are not 100% resistant to dirt and particles.

1 people found this helpful.
40

The industry standard is 96% and K&N meets those requirements. I doubt the validity of the these independent tests. Botton line, I installed one on my GTI and there is about a 3% increase in hp BUT the throttle is more responsive and I actually can hear more of a growl!

3 people found this helpful.
10

regarding KN performance I do notice a small amount. I drive often and lots of miles per year. the last KN filter I used for over 100,000 miles with no damage to my engine in all weathers so negligible particles do not get through and the bonus is the durability of the filters, sure they cost more but you never have to replace them (unless damaged). I just remove the KN, wash it out every 50,000 miles or so and coat in a thin layer of engine oil then replace. just remember to tell your garage not to replace the air filter when you service your car. works out cheaper than changing the paper ones every 15,000 to 30,000 or so. iv used KN filters for years on many cars and never had a problem. and no dealer or mechanic has never told me I shouldn't be using them.

1 people found this helpful.

Bought my 2006 mustang gt new in Sept. 2005. Replaced stock air filter with K&N drop in filter and noticed an immediate performance boost. 0-60 times 2/10's better. 5.1 to 4.9 (auto trans and 255/50's). Best thing is increased throttle response. Stomp it with K&N and paint long black burnout lines without power braking.The car could not do this with stock filter. Same performance now with 30k miles and have not touched the filter.

10

1-3 horsepower, which is about what you would see in a temperature drop of 5 degrees

1 people found this helpful.

Without changing driving habits I got a 1mpg increase. Hard to tell if there is much of a difference in HP. My truck (F150 3.5L Ecoboost) has always pulled and accelerated like a banshee. With that said I really got because of money savings over the life of my truck not having to buy air filter after air filter.

103,775

Just the filter won't gain you much if anything but if you go with the upgraded K&N intake system you probably will gain several HP especially if you upgrade the exhaust too. I think K&N can back up their claims with dyno data. Don't use engine oil, use the correct air filter oil!

I heard from some folks who have a K&N Air filter that it ranges from 4 to7%. I'm guessing with my 2012 Camaro 2SS with 400hp without the K&N Air filter (Auto) that it will range from 416 to 428HP new HP ratings. 400HP x 4% equals at least 416HP. your thoughts?

5

gives increased airflow and better throttle response if you have a turboed car youll hear the difference in the sound of the turbo spool

35

ABSOLUTELY POSITIVELY NONE ON A STOCK ENGINE!!!!! NONE!!!!!!!!!

35

All these people claiming they've gained 1-3 hp are total freaking idiots!!!! How do they know, because they "THINK" they can feel the difference when they mash the gas pedal down???? I don't hardly think so!!!! In a car you will NOT notice a 1-3 HP gain!! 1-3 hp gain is barely if at all noticeable on a 500 lb motorcycle let a lone a 3500-4000 lb car!!!! The only way to tell if you've gained any hp is to have your car PROFESSIONALLY run on a dyno machine and those numbers will tell you that hp gains with a K&N are minimal at best!!!!!!!!!!! And even if you did run your car on a dyno and gained 1-3 hp, those gains could be attributed to a number of things besides the air filter like air temp at the time of the dyno run, humidity at that time, barometric pressure, tire pressure at the time, fuel etc etc etc. 1-3 hp can be had or lost from day to day depending on those factors and those factors alone and not because of putting in a K&N air filter.

1 people found this helpful.

I put a K&N on my 05 Stang...great throttle response. plus i changed out the stock headers for BBks and 40 series dual flow masters with an x pipe. car runs mean and sexy.

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