Ran this oil for 6 months this summer. Like the last run with the Pennzoil Euro 5w40, viscosity was a bit low for a 40w according to Blackstone. I also installed a performance intake from Injen a few weeks into the OCI. Did it gain any power? Who knows, who cares. I just wanted the noise. It's fun how you can play around with the engine noise depending how hard you press on the throttle. Thankfully the filter seems to be doing it's job.