I think people are overly cautious with these things and ultimately end up wasting money. It's like a 3000 mile oil change. Get some calipers and see what the thickness of the metal is. Compare that to new spec and make an actual determination based on fact. Mine didn't look much different than ^^^^ and it had over 50k on it, on a Stage 2 APR tune. 5k, and even 10k seems excessive. I get the whole, $50 is cheaper that replacing your engine but come on....at some point it gets ridiculous! I'll also give you the argument that each car is different and each follower will wear differently. Which is exactly why you should put calipers on it and check it every 5-10k, or with each oil change. When it's more than a reasonable degree out of new spec then replace it. Otherwise it's just money down the drain.