K&N Air Filter in M35x

[lagalaxy8]

Has anyone upgraded to a K&N Air Filter and did you feel it was worth the extra money. Still plan to keep the car for a few more years. so weighting this over regular paper filters.

[Larz]

I was considering dooing a cold intake with a K&N cone filter until I researched what difference I could expect. Based on what I found, there is NO conclusive evidence that performance changes by more than a couple extra HP. In fact, there are tons of tests that show it can even reduce HP and in NO cases did the air temp show much reduction after hundreds of dollars spent on CAI kits. If you want the look, go for it. Otherwise, it's a waste of money and time.
My reason? Common sense and research by experts.
1) the OEM M35 air intake is just under the leading eedge of the hood - as close to outside air as possible.
2) the cone CAI kits pull air from under the hood right next to the HOT engine. How anyone could think this will be lower temp air is flying in the face of pure science and physics.
3) unless the CAI kit comes with a built-in fridge to cool the air on the way to the engine , its bollocks plain and simple as proven by Moog & Marty below. If you want more power - you need an actual TUNE.
.
http://www.youtube.com/watch?v=gCi2yo4UqPI
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As for air filters inside your stock housing ... K&N are re-useable only if you wash and clean them and they don't make any difference in performance. I fancy a brand new clean filter with every change. Een the Infiniti brand OEM green filters are less than $20 and I change mine once a year (and it doesn't even look dirty - I just change it anyway).

[lagalaxy8]

Yeah wasn't looking to do a cold air setup, just the filter.
I've had k&n on cars in the past, most came on the car already, so I have the kit to clean them and normally do during an oil change sometime in the summer. I don't drive a certain car too many miles and not in dusty conditions so most filters last for quite awhile.
Just wondering if I should spend $40 or less for a filter I can get at Walmart. I'll probably only change once in the life I own the car.

If there was a slight mpg or something gain I'm all for it because the MPG sucks on this car. My 2 over 20 year old Lincolns with v8's get better mpg's.

[EniGmA1987]

There have been reports by quite a few people who have said that after 1-2 years running the K&N filter their mass airflow sensor goes bad. The theory is that because it uses some sort of hot wire system that some of the oil comes off the filter in micro droplets and builds up on the sensor over time (sensor is located just behind the filter) and because the oil coats the hot wire the sensor burns out. Don't know if it is true or not, but there are an unusual number of people who had their airflow sensors go bad who all upgraded to K&N filters. Since you wont get any real HP increase by the filter change I prefer to stay on the safe side and just use the stock filter.

[lagalaxy8]

Thanks for the info, looks like I'll pass on one.

[CPJ LB]

I've run OEM filters, K&N, and Purolator... To me, I think Purolator didn't work well, I noticed a drop in mpg's - it felt as if it wasn't free flowing...

The OEM filter worked great due to the tight suction it had while in the air box. the rubber seal around the filter frame is thicker than others. I use an OEM filter when getting my car smogged or when I wash the K&N...

The K&N drop in works well...there is a noticeable difference when I switch from the OEM to the K&N. I see the difference when my car is dynoed. whether it's a little hp bump compared to OEM, it's still adds to the total... I prefer the K&N due to the fact of being able to use it longer (of course washing it when necessary)...One K&N is more cost effective in the long run than having to buy many OEM filters -- even though I keep one OEM in storage for my smog testing...

As far as the MAF sensor being damaged, I believe it will happen to those that use too much re-oiling or don't dry the K&N thoroughly after washing... there is also a spray cleaner to use on the MAF sensors...using this is beneficial.

I've run K&N air filters in several of my cars and had no issues with the MAF sensors. In fact, in my E350, Mercedes requires TWO long air filters in the E class - still no issues there when using K&N. And dealers never gave me issues when seeing I had K&N filters

To each his own...hopefully this helps. I currently have approx 139K miles on my 06 M35 and it runs good...

[szh]

Thanks for the info, looks like I'll pass on one.

Good!

Yes, people say they have had good experience with oiled filters, but many Nissan folks have had the opposite. Our hot-wire MAF systems on Nissan engines are particularly susceptible to problems with these filters ... many posts at NICO attest to that.

The supposed gain in HP from the K&N filter is imperceptible enough that this effort is not worth it. Using a regular air filter and changing it often is likely to be a better thing to do.

Z