I just recently purchased my S2K. I had the oil changed, had a multi-point inspection done and I put in a K&N Filter. I typically put a K&N in my vehicles since I feel they pay for themselves in the long run, but I also believe there is a noticeable increase in HP and mileage. While I've been able to tell the difference in other vehicles, I can't say the same for the S2K. The stock filter is apparently a good design. Putting a K&N is still going to save $$$ in replacements costs over the life of the car tho'.

 

installed my cosworth filter last night
oem filter was dirrty

 

I bought a K&N and cleaning kit for $60 one year after I had the car. Manual states filter should be changes ~yearly, so in five years I've cleaned my K&N for no cost other than time, once-twice a year. A new paper filter was $28 when I checked, so if I bought one filter each year that would be ~$150 vs $60. Even if I went two years on one filter I'm still ahead.

 

I am running the aFe dry filter. I was going to get the cosworth filter but was informed that it should not be washed and reused. The aFe filter was about 90. Pretty easy to clean, you can tap it on something to knock debris off or rinse it off. No oiling needed. I clean mine every 5-10k miles.

 

Pay the $ and install OEM filters.

K&N Filter tests

 

I'm using an AFE air filter. Replaced the Comptech sponger filter. Nice quality filter. Before going FI, I was using a JR filter.

 

I'm actually surprised how well made the Honda oem filter is for a factory part. It's a nice design. It has more than enough filter area, I recently read a calclulation that it is larger than the two filters that supply the Dodge Viper 8 L motor combined. It has an air horn built into the base of the filter which is a nice design feature, along with the shape of the piece.

The price you got for the oem filter sounds quite high, I just paid under $20 for mine last week from my Honda dealer, and we usually get hosed for parts compared to the US.

 

JR Filter...

 

Its paper but its oiled. That green tint you see = oil!

 

I went ahead and just bought a factory filter from the dealer today. It ended up being 34 bucks and change. Noone in town stocks the K&N or any other aftermarket filter and I would have to order one and wait a few days. I'll run this one until it needs changing again. meanwhile I may order a K&N or another aftermarket dry type of high flow filter and store it until next change. I appreciate all the input. Oh and BTW the new factory one I picked up was sealed in bubble wrap and was indeed pre-oiled.The old element material/paper was green in color and the new one was blue. Not sure if age turned it a green tint or the element material is different. Cheers.