No, I didn't expect any either. I bought them for the tiny bit of extra flow on the hottest days [longevity/washability being the secondary benefit]. So far I haven't noticed any lag and we've had several consecutive days of intense heat this summer already. I'd have to switch back to the stock filters to know if the K&Ns are making any difference though. I've used K&N in the past, and with a tune you can eek out a bit more performance versus stock filters. So I know there's performance there, just not sure if Kia's engine tune will take advantage of the additional flow on its own or that the percent or two bump would even be noticeable.