Which air filter is better or are they all the same? Does it make a difference? Which is more fuel efficient? Injen or the k&n? I want to replace my air filter from the air intake. I just don't know which one is used the most by you guys.

 

With the stock air intake, I don't think it makes much difference. I use Mann:

 

I wish but i have a custom air intake.

 

Pop (charger)hold it down....!!!

 

Aem

 

pop charger X2

 

Aem dry flow filter

SAK74

 

JWT pop charger +3

 

Aftermarket air filters are pretty much the same and you will not see tremendous gain.

 

Performance is generally the same and minimal at best although you'll squeezed a little more HP up top with supporting mods and a tune. A lot of people like the foam filters but I have used the oiled K&N on my last 3 cars with no issues (just be sure to maintain).

The aggressive sound of an intake is usually the best benefit.

Oh, I have a Berk set up with K&N.

 

I changed the filter acouple years ago it might of been stock even.
It was a red nissan filter with a metal frame it had a huge amount of sand coming off the pleats and the bottom of the box also had a ton of sand this thing was clogged. Super clean on the inside there wasn't a thin layer of dust it was just clean. Did it's job real good.

 

I bought a K&N for my 03 Maxima around 4 years ago and no problems at all with it. Very happy with it. Just need to remember to clean it properly but easy to do.

 

K&N, in long run, it will save you money.

it was said it could benefit your fuel efficiency, but I highly doubt it. Reports say that more likely it could increase your acceleration and horsepower, but not your gas mileage.

But anyhow, it is a great air filter.