I've said in the other K&N threads - if you are a daily driver type person in average car driving in average ways, these are just not worth the cost or hassle vs. cheap paper replacement filters. If you are chasing power on a modified or performance car, then have a go b/c 5 hp is 5 hp on the top end (if you can get it with one of these) and the little bit of fine dust (if any...will depend on your conditions) that is getting in is the least of your concerns w/r to longevity of your tuned-out boosted to the limit engine. I've showed my UOAs in the other threads that show excellent filtration using both a drop-in K&N as well as an open-element intake with a K&N cone filter by the analytical metrics available on the UOA (silicone and insolubables according to BS) and shown pics of my intake tube that is clean/dust free when I wiped it with a paper towel. I see zero downside for me and only upside. I run them in all 4 of our cars.