I’m pretty sceptical about these “add on” products to be honest. I have a 2008 FG Falcon XR6 Turbo that has only done 37,000 kilometres. I have run it on Penrite Racing 10W40 since new & oil is changed every 6 months due to extremely low use, so oil is quite clean anyway. I bought the oil flush on a whim, not expecting anything. I used it as per the label and was surprised at the colour of the oil that was discharged. It was certainly “dirtier” & darker rhan usual. I hope this is good, and I assume it is if it’s releasing sludge, etc so I’ll keep using it.