Paul, nothing wrong with your question. The answers to K&N questions in general are in the archives, but I don't recall anyone asking about that lid thing before. Either way, no problem asking any question as far as I'm concerned. The only reason I joined in and made that comment is due to the abundance of "K&N is great" posts. And as usual, I wish I had just ignored it…
Look guys, it's not a pissing match, or at least it is not for me and should not be for anyone. I have nothing to gain either way, and I've recently (nearly a year ago) wasted my money on a UNI filter (similar K&N, but does test better) because, at the time, I believed that the extra flow would help a diesel due to it's HUGE need for air and the turbo. I WAS WRONG AND WASTED MY MONEY. So if anything, to keep from admitting I was sucked in and wasted my money on the filter and cleaning kit, I should be supporting the pro-K&N crowd.
I keep swearing to stay out of these discussions, but I keep getting drawn in by a concern that the "myth" not be propagated further.
Yes, there are tests for these type things. And yes, they have been run over and over and over by magazines and various other interesting parties. HP, Torque, MPG, and all of them have been tested time and again on trucks and cars with different configurations. Of all the results, NONE that I am aware of show any significant performance difference between good quality clean filters. But those tests that check for filtration quality do show a rather large difference in filtration quality, and K&N is by far the worst in that category.
The problem is that SO many people have bought into the K&N hype and advertising machine and they will vigorously defend K&N against any negative comments regardless of facts to the contrary and having no solid supporting evidence. Most ("all" would probably be a safe bet) people supporting K&N can offer no more than anecdotal evidence to support the case for K&N and for some reason refuse to accept any test data except for K&N propaganda. And the supporting claim that "they've been a player for X years" also does not hold water. Show me independent dyno tests where like and like are tested and it made a significant improvement in HP or Torque (peak, flatter, mean, curve, anything). Show me controlled tests that show mileage is significantly affected. Hot Rod and other magazines which get PILES of K&N advertising dollars have run these test, and even they could not spin it as a worth while improvement based on the numbers.
And I've never said there was NO reason to run one, just that the VAST MAJORITY of people running them are getting absolutely NO performance benefit from them. If you like the bling factor, or the reuse, go for it. But that's all you should realistically expect out of it. Don't expect performance increases unless you've exceeded the flow available from the stock type elements, and it is VERY unlikely that you need more flow in any street-able engine. And please don't start telling everyone else, particularly those new to the automotive hobby who know no better, how great they are unless you can back it up with something besides K&N propaganda. If you have data from anyone other than K&N (obviously this source has a conflict of interest) to the contrary, please produce it. Test that back up my stance have been produced in the past, but I'll leave it to those who care to go find it…
<shrug> Like I said, if you want to know more, this was discussed at length on at least two threads I remember in the last 6 months or so.
Now that I think about it, we shouldn't even be talking about K&N in general. The topic is the lid, let's try to stick to it…