I've been using this oil since about 5k miles or so. I'm currently at 15k. I'm going to do a Blackstone analysis on the oil that is in there now, which has about 4k miles on it. I did a 50/50 mix of 0w30 and their now not-available 5w-50 Racing oil. I'm sure some you won't approve mixing viscosity for whatever reason, I don't care. I'm about to put in run their 5w40. Its PAO-Ester based, cheap and relatively readily available. I'm not saying its THE BEST oil, or everyone should run out and get it. But I've had no issues with it, and that includes many track days. Horray for oil.