I guess I must be one of the first here to use the StartUp product. I put 10w/30w in my 2002 Subaru Impreza TS 5m with 32800 on the clock. I used an Amsoil SDF20 filter, and changed my air filter from K&N back to stock. I posted asking what to use in my car a week ago or so. Of course I ignored all advice once I got to Walmart and was standing in the oil aisle. So many choices! That place smokes the AutoZone! I wanted to try the Delo, Delvac, or the Rotella Syn, which is a screaming deal at $12 or so, but due to additional questions that I've asked in another thread, I'll wait on that. So I was looking at the Havoline, Chevron Supreme, Castrol GTX, and some of the blends. Then I saw the StartUp, and thought what the **** , I would probably spend $7.50qt on Redline, why not $2.90 on this? So now I have the StartUp in there, and a Blackstone kit at home. How long should I go before I mail off a sample? I drive pretty aggressively, but understand the N/A Subarus are easy on the oil. Any of you interested in a test on this? BTW, my car feels great, better than it has in a long time. The idle is smoother. And of course I have great peace of mind knowing that I have zero start up wear now !