Actually, I will respectfully disgree with the two previous posters on whether or not the K&N is worth the $$$. Yes, it actually is. I go over this all the time with folks. Here is why.
The first thing you have to understand is there is NO drop in filter that is going to give you any kind of real HP or torque increase. That is a myth plain and simple. If you want to increase HP & torque then install a CAI kit.
As to MPG increase. I have run K&N drop in's for years in my Rams( 2 360's, 1 4.7L, and now my HEMI ). I see approx a .5MPG gain using them. Nothing really significant but a slight increase.
A K&N drop in will also let your engine breathe a bit easier than the standard paper filters. This may equate to a .5-1.0 HP gain. Again, nothing you are going to really notice.
The real benefit to using the K&N is actually the cost factor. If you are not going to run a CAI that means you will need to run a standard air filter setup. Paper filters may go 10-12K max before they need replacing. I think the manual on my 04 says 15K but NO WAY that is too long. I always replaced at 7500 +/-. Anyway...
The cost of a regular paper filter is going to set you back in the neighborhood of $25-$35 to fit our HEMI Rams( also fits the 4.7L Rams ). The cost is CRAZY for these fitlers for some reason. The K&N drop in filter will run you approx $60( +/- $5 range depending on where you buy it ).
You can go 50K on the K&N before you either A) - replace it or B) - clean and recharge it( cost $19 for recharge kit ). So, when you look at the following numbers you will see just why the K&N is worth the money if you are going to run a regular air filter setup.
Here we go...
50K w/ K&N = $60
50K w/ Paper filter:
Option A) changed at 10K means 5 filters @ $30 each( I will use the average price ) = $150
Option B) changed at 15K means 3 1/3rd filters at $30 each = $100
Now, that means you save $40 to $90 on air filters over the 50K interval and you have a filter that works better, lets your engine breathe a little better, requires no maintenance or care on your part during the 50K( it is pop it in and forget it basically ), and even gives you a slight MPG boost.
Now if you look at 100K which is about how long most folks would keep a vehicle that would mean you would have to deal with the K&N filter at the halfway mark. So you can either replace it and pay another $60 or buy a kit for $19 and clean and recharge the old one and reuse it.
So at the most you will spend $120 on 2 K&N filters over 100K. Clean, recharge, and reuse the same one and it is less than $80 for 100K.
You will also only have to deal with the AF 2X's in that 100K.
Or, you can run standard paper filters which do not work as well as the K&N drop in, you will have to deal with changing the AF 7-10 times instead of 2, and you will spend $200-$300 over the same 100K.
All in all the K&N drop in most definitely is worth the $$$ as long as you understand why. If you want more HP/performance than it is not what you want. Get a CAI for that. If you are going to run a regular air filter set up it is a great investment.
You pay less, you don't have to change it as often, you get a slight MPG boost, and you get better filtration performance( while still allowing the engine to breathe easier )out of the AF than you do standard paper ones.
K&N = two BIG thumbs up!! This message has been edited. Last edited by: NHHEMI, document.write(''+ myTimeZone('Thu, 07 Apr 2005 13:44:51 GMT-0700', '07 April 2005 04:44 PM')+''); 07 April 2005 04:44 PM