When the opportunity arises I do (maybe really hard once a month when I work into the wee hours). I do push it up to red-line probably at some point every day but it is not as sustained as track driving would be.Thanks Mike, I just talked to Joe yesterday and he said the same thing. Which leads me to the question " why did I receive the older ones ". I purchased these headers in April. Anyway, its nice to hear that you've had them a year without issue. Do you drive the car hard?