I'd like to know how the tests were done. I don't have a k&n and I've never seen one. This topic has been beaten to death many times and I've stayed out of the last several but you're the first I can recall to actually bring up 'efficiency' ratings. IMO, these are irrelevant since the tests were not done the same way. Also, is K&N's rating a 'cleaning' efficiency or a pass-through efficiency? Also, many have commented on how just looking at a k&n filter, you can see right through it and I think the general consensus is that larger particles can get through the k&n. However, the main reason I'm not getting one, is because based on what I've read on this board for the past three years, for every person who says they can feel a difference, somebody else says they can't. Also, I'm not interested in the potential cost savings as I'd rather just drop one in and move on then have to clean and oil the one that's there and also check to make sure it's still there after a volvo servicing.

Is harm being done to the engine by larger particles being allowed to get through? Most likely. Will I notice this? Most likely not. Unless of course I decided to go offroading in the desert.

pat